Flight baggage

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For flying, there are two basic types of baggage: checked and carry-on sometimes referred to as "hold" and "hand" luggage, respectively, the latter even "cabin baggage". Checked luggage is usually given to airline staff at check-in time and, after electronic or hand screening, transported by airport crew to temporary storage and loaded into the hold of the aircraft.

Different flights and airlines have different baggage rules; see planning your flight.

Understand

For many reasons, air travel has some additional restrictions when it comes to your baggage. Passenger planes tend to have less space for your baggage than other types of transportation. More importantly, as the plane will have to take off and stay in the air, the weight it carries matters much more than for land based-vehicles (for example in 2003 Air Midwest Flight 5481 crashed due to overweight). Likewise, any incident onboard tends to be more serious if it happens in the air, where it can't be dealt with like on the ground - therefore some things that can be brought onboard other types of transportation are banned on airplanes and luggage is screened upon departure.

Therefore there are many things to take into consideration when packing for a flight — what you can take, where to put it, and what's useful to bring for the flight itself. This article will deal with these topics.

Checked luggage is often tossed about in transit (and in turbulence during flight). If you have something that might not survive such handling and it is allowed on board, carry it on board. Otherwise, leave it home or consider shipping the item. Travel insurance often will not cover fragile items broken in checked luggage. Applying a FRAGILE sticker to checked luggage (perhaps provided by the carrier) is rarely sufficient to change the way baggage handlers care for bags.

Prepare

See also: Baggage

As you choose any case or bag for travel (at home or purchase), mind its empty weight, dimensions, ease to carry and apparent durability, e.g., well-made rollers and comfortable handle.

Traditionally any airline ticket included one large suitcase to check in, a small one to place in the overhead bin and one additional item, such as a purse (handbag). Nowadays you may save money by packing less, making "carry-on only travel" (see below) a popular option for shorter stays. Don't count on budget airlines being cheap without checking what luggage fees they have.

Suitcases are usually made to fit the airline allowances, but these vary somewhat between airlines and regions. There are also variations on wheeling and hardness; a hard-shell suitcase protects its content better, but may be difficult to fit in a tight overhead bin. Soft-shell suitcases tend to have more compartments. Soft, partially-full bags or sacks may fit in smaller or nearly-full bins where fixed-shape luggage can't. Lighter cases allow you to pack more. A suitcase that opens from the top (when laid down) may be handy in tight hotel spaces where clamshell suitcases lack sufficient space to open fully.

Very large pieces tempt packing too much; they may violate weight or size limits. You might want to have some leeway with the dimension limits and avoid such cases.

Carry-on luggage is what you take with you to the passenger department. The restrictions on size and weight are more severe than for checked luggage, but this is where you should put what you need during the flight and in case your main luggage gets lost, valuables, and things that you want to handle yourself instead of them being thrown around in turbulence and by careless staff. Typically you carry one smaller suitcase and one additional item, such as a handbag, but there are ways to get in more than what would normally fit in these.

Some suitcases have "smart" features such as built-in luggage scales, the ability to connect to electronic devices, etc. If there is a lithium-ion battery, make sure that it is removable, especially for checked pieces, since such batteries are prohibited from being placed in the cargo hold.

Carry-on luggage

Carry-on luggage is taken on board the flight, and restricted in size and weight, nearly always for one item besides a purse, a modest bag or such. It must fit in overhead aircraft bins or under the seat in front of you (if there is one). To preserve your foot room (crucial on long flights), you'll want to put as much in the overheads as possible–and so you'll want to choose each piece of "carry-on" carefully when bought and when you start packing. Fixed-shapes from quality brands should be sized to fit "standard" overhead bins, e.g., up to 22 in (560 mm) long roll-ons for large Boeing and Airbus aircraft. Still, choose carefully. In addition, many flights (in Europe and elsewhere) use "regional" jets or turbo-props with small overhead bins and little room under seats. The "official" "Euro standard" is 20 in (510 mm), but even such a case may not fit in bins of many regional jets.

Generally, each passenger may bring one piece of baggage typically not exceeding 20×40×55 cm and an additional piece of luggage such as a purse (handbag). The primary "cabin bag" is typically one designed for the dimensions allowed on regular airliners–to fit in overhead bins or under seats.

Small aircraft may have tighter restrictions. Most airlines also limit the weight. Still, never put high-value or irreplaceable items in your checked luggage. Discussion below will help you work around these limits.

One exception for carry-on luggage may be granted–when a traveler must take a medical device essential to his/her health during travel. If small enough to fit into a "cabin bag/case", the airline may allow a second bag. This always requires advanced permission, with proof of need from the doctor. (Consult the airline after booking.)

Advice about generally what to pack in carry-ons includes:

Somehow you need to carry all your official/valuable papers, cash/bank cards/passports and high-value items (e.g., jewelry, electronics/camera, medical prescriptions or irreplaceable medications) with you. Checked bags occasionally get misplaced/miss-routed, have items stolen, or a personal emergency during flight may demand immediate access to medication or a personal item. Most travel insurance and airlines will not cover such items when placed in checked luggage. If you have a personal item along with your carry-on, place your most essential items in the smaller personal item, in case the carry-on bag needs to be gate-checked.
Understand what liquids you're allowed to carry on board, e.g., see the TSA 3-1-1 rule also discussed below, with metric equivalents adopted virtually worldwide. This includes foods made with syrups/gels/pastes, e.g., peanut butter, jams, jellies. If you consider packing such, keep them within the 3-1-1 Rule.
You may want or need to include some comfort items (discussed below).
For vacations, you'll likely want a camera, perhaps a laptop or tablet. (Consider putting their support accessories in checked bags because not valuable per se, so not interesting to thieves.)

Fortunately, cameras, laptops/tablets, purses and outer garments may fall under separate allowances. This can give you some relief and packing options, e.g., in addition to a modest backpack or small suitcase:

You'll probably be allowed to carry on a modest camera bag.
The "purse allowance" doesn't specify gender.
- Women can choose one that is rather generous–but not outrageous.
- Men may be allowed a modest shoulder bag, small backpack or sack.
Some travel-item sellers offer coats and vests with many pockets, able to hold many small items. You may already have one.

All may help increase what you can carry-on, and (except for budget carriers) probably won't be protested or result in a fee unless you over-do it. In most cases, you should put the larger bag in the overhead bin, and any personal item under the seat. However, if they both individually fit under the seat, put the bag that you won't need during the flight in the overhead bin—especially if you have a window or middle seat. Note that first-row seats don't have any space for personal items.

Pack no sharp or weapon-like objects in carry-on baggage; if seen (likely), they will be confiscated. Even "convincing-looking" toy weapons are illegal in many countries.

This includes pointed scissors (however small), pocket knives, Swiss Army knives, screwdrivers or similar tools, baseball bats, martial arts weapons, and so on.
Pack sharp items in your checked bags in ways that don't create risk for baggage inspectors.
If passing through the USA, check the list of prohibited items at TSA.

Pressurized containers, explosives, weapons (or items that look like weapons) and other hazardous materials are prohibited entirely. For the USA, see the TSA's guide to Transporting Special Items^{[dead link]}.

Security limits for liquids, gels and pastes

IATA guidelines apply the 3-1-1 limits (in metric equivalents) to all international flights. They impose 100ml or 3.4oz limits on all liquids, gels and pastes in carry-on baggage. This includes aerosols, toothpaste, deodorant/antiperspirant sticks, all drinks (including water), etc. that you try to carry through the personal security check.

All containers for those liquids must fit in a single clear bag/pouch smaller than 20cm x 20cm or 1 quart. Each container inside must meet the 100ml/3.4oz limit (e.g., a 250ml toothpaste tube with only a small amount of toothpaste left is not allowed). If you want to fill your personal bag to the max, freezer bags are more sturdy than basic quart "zip locks".

These restrictions are usually enforced at terminal security checks. Some exceptions are possible, e.g., for medical necessities or baby care items. Sanitizing wipes individually sealed in packets are allowed and highly useful in-flight.

Duty-free items purchased within the secure area of any airport that exceed the 3-1-1 limits may be allowed on board. But be careful of en-route terminal changes where you may have to re-check through security. Even if sealed in a tamper-proof sack, containers of liquids originally bought "airside" elsewhere may not be allowed through "re-check".

Place all medications and the bag of 3-1-1 liquids where they can be easily seen at security check. Ensure all medications are kept in original bottles and clearly labeled by the issuing pharmacist. For international travel, if you want to sort medications into daily/weekly dose containers, wait with that until at your destination (if presorted before travel, customs officials will have no proof of the contents and may declare all as contraband). Place all other liquids not meeting the 3-1-1 Rule in your checked luggage. You may be required to demonstrate the harmlessness of any liquid you're carrying on request by security officials.

Expect to discard all liquids and gels you carry through the security checkpoint that don't meet that country's regulations. Details for the United Kingdom can be found at the Security Control section of the official Heathrow Airport website.

Food and water

At least if your flight goes to the United States, Australia, or New Zealand, take no more fresh or un-packaged food than you will eat before you arrive – as carry-on or checked. Those countries have strict rules about bringing in food. Overall, if flying internationally, especially between different continents, there's a good chance there are regulations on bringing in food, to prevent spread of diseases and pests — do check this beforehand to avoid trouble! The food will be seized, and if not properly declared, may generate an immediate fine or worse. If you bring too much food, make sure to throw it in one of the provided amnesty bins before reaching customs and quarantine. On long flights there will probably be a meal or snack served (or offered for purchase) anyway. Check at least before boarding.

If you are hypoglycemic, diabetic, or have blood-sugar issues, you might take a few non-perishable, packaged snacks. Again, don't count on being able to buy such items at any airport.

For getting water, refill an empty bottle (ideally collapsible) after security check. Failing that, bottled water at the airport is usually overpriced, but may be available onboard the aircraft, especially on long-haul flights, although budget airlines may not provide any.

What to pack and wear

Especially for long flights, the right kind of equipment can make the journey more pleasant.

Amusements

Unless you sleep easily on flights, you might want to keep yourself occupied, especially on long flights. Five "empty" hours may be tolerable, but much longer can go beyond boredom. Some planes have the latest in-flight entertainment systems, recorded music/movies/TV episodes, and on-board games–with visuals presented on a small-screen TV. Others may have little or nothing. Visit your airline's website or sites such as SeatGuru to check. You'll need earplugs or earphones to hear entertainment audio. For long flights, some carriers offer them–often for a fee. If you plan to use your own headphones/earplugs, ensure you have electronic plug adapters. The airline's web site should list permitted electronic devices; on board, look in the in-flight magazine to find the "rules". Perhaps even better than all this, treat yourself to a good book – electronic or hardcopy. On one hand especially hard-cover books can be heavy (mind weight limits), on the other, hard-copy books are easier on the eyes than displays.

Comfort items

Some of these are mentioned elsewhere:

For warmth, consider a light jacket, vest, wrap or small blanket; if clothing, wear it aboard (won't be counted as a carry-on item) then remove it as you take your seat if not needed. If you have a window seat, have something to shield your legs from the cool wall.
For sleep on longer flights, you might want a neck pillow or something that keeps your head upright.
For very long flights, savvy flyers bring something to pad the small of their backs (e.g., cushion or roll) and slippers.
Smokers may want nicotine gum for long flights.

For your consideration:

If not interested in entertainment audio, consider a pair of foam earplugs. Even on short flights, engine noise or a restless small child near you can be bothersome. The announcements can also be annoyingly loud, because they have to be clear even with engine noise. Plugs can reduce the noise level but still allow you to hear instructions in an emergency—or
If you're a frequent-flyer or going on a very-long flight, consider quality noise-canceling headphones or earplugs. They help much more than foam earplugs. Choose carefully for long-term comfort.
Lightweight blanket. Many airlines no longer offer them, especially for flights less than 5 hours or so.
Newspaper, for reading, and to insulate against the cabin wall if needed.

If you put electronics (e.g., music player, headphones, laptop, cell phone) in your carry-on bag, electronic screening is more likely to generate manual inspection; so pack them to be easily seen. In most countries, laptops and "E pads" are scanned separately from other carry-ons; you'll have to remove them from any carry-on luggage holding other items. Make sure their batteries are charged at least enough to boot them up for a simple demonstration.

Most regulations allow you to carry on an umbrella if it fits in your bag, the overhead bin or under your seat. If you must have a type that won't fit, consider putting it in your checked luggage or buying one at your destination.

Airline gate security may confiscate any carry-on item they feel is "suspicious", often without recourse. At that point, you would not be able to put those items in your checked baggage, because by then it would already be waiting to be loaded aboard your aircraft.

Clothing

See also: Clothing

Cabin temperatures may vary during flight. Experienced flyers dress in layers that they adjust to need for comfort.

For cabin comfort, you might use a soft jacket for warmth or as a blanket or pillow. Such items are usually offered on long flights, and/or in business class.
Warm socks/slipper-socks can be useful if you wish to doff your shoes on a long flight. Wear your shoes when walking to the toilet, as their floors may be wet, even filthy. Cabin walls and cabin air near exit doors can get quite cool due to outside temperatures of around –40 degrees (Fahrenheit or Celsius, both scales being the same at this temperature). If you have a window seat, you'll likely need something to insulate against the wall–even a few sheets of newspaper can help remarkably. If near an exit door, you may need all the clothing layers you can access, especially if you can't get adequate blankets.

Between different climates

When leaving a cold region for a warm one, consider leaving major winter wear with friends if they'll take you to the airport and pick you up on return; this can also lighten your luggage.
For travel to a cold region from warm, use layers and carry at least a lined jacket; it may be some time before you gain access to the warm clothing in your checked baggage.
Airplane interiors may not be cleaned as frequently as you'd like, especially on budget airlines. If important to you, consider wearing something in-flight that you can doff soon after disembarking, to wash/clean it later.

If traveling for business, don't put all work wear in checked bags. If it goes missing, you'll need one complete outfit–between what you wear on-board and in your carry-on luggage–to conduct business adequately-dressed.

Medical/first-aid kit

See also: Flight and health

In addition to the special medications noted above, you may need a kit for minor "incidents", e.g., cuts/scratches, stomach upset, slight infections. This article from the U.S. Center for Disease Control suggests the what and why of what your kit might contain. Need for some items will vary according to the length of your trip and where you'll go (e.g., distance from where you can purchase items as needed).

How much should you pack?

See also: Packing list

Once you have booked your flight(s), go to the airline's web site to fully understand its baggage limits and fees. Most legacy US carriers and low-cost carriers outside the US levy fees for checked bags; at least one airline also charges for carry-ons. Fees paid on-line, in-advance may be slightly less than when paid at check-in.

With codeshare flights, your bottom-line luggage allowance may not be the same as the airline you are booked through, or the airline indicated by the flight code. The rules of the actual airline operating the flight apply. If you are a frequent flyer with status be particularly careful, as any increased baggage allowance you have when flying with your airline will usually not apply to the codeshare flight.

Use a scale to weigh large baggage or packages before you go. Once you place your bag on the scales at check-in, some airlines will not allow you to take out contents; even if they do, it's an embarrassing hassle.

The easiest way is to purchase an inexpensive luggage (hand) scale that consists of a handle, a small (preferably) electronic scale, with a large hook–not bar. Hook the scale to the handle of the bag, and lift it up totally off the ground using the scale's handle. The weight will be shown on the display. Avoid buying any scale that won't measure well beyond the airlines' weight limit (e.g., 50 lbs.), or that can't switch between pounds and kilograms. Take it on your trip for use just before your return flight.
Before initial departure, you might indirectly weigh items using a bathroom weight scale. First weigh yourself holding your bag completely off the ground, then without the bag, and note the difference. Ensure you follow directions for use (i.e. hard, smooth surface only--not on a carpet or rug).
For your return flight, if you don't have a hand scale, you might ask hotel staff if they have scales to use.

Don't take more luggage and contents than you can carry/roll by yourself, including items needed for infants, children or the elderly.

Airports generally have baggage carts for rent, but you'll often need local currency (usually coins) to "rent" one. Others may accept major credit/debit cards. In some countries (e.g., the UK, the U.S., etc.), you cannot take these carts through security checkpoints into secure/airside areas.
Some airports offer free carts–more often in areas for arriving flights.
Nearly all airports and hotels have porters, usually working for tips. In some airports these must be booked in advance.
Elsewhere, you'll likely be entirely on your own. Too many bags or too much weight can become a major burden.
With separately-booked flights to a destination, you may be wholly responsible for claiming any checked bag(s) at the end of each flight, taking it to the next airline check-in counter, re-checking it for the next flight leg, and getting to your next flight on-time–take care with connection details.

If you take as much as you are allowed, purchases on your trip can make your bags overweight or "over-stuffed" when you return, resulting in airline fees beyond those for starting the trip. This can greatly increase the real cost of even the best bargains. Some experienced travelers with shopping plans even take and use some presentable but older garments, etc., then donate or discard them before returning home.

If you were close to the allowed weights outbound, make sure you wear the same (weights of) clothes back home. If you go to a tropical isle wearing jeans and jacket, and return wearing flip-flops and shorts, with checked bags holding the heavy clothes, you could have luggage weight problems. If you have laundry that is still wet or you were drenched in a shower and changed clothes, this can cause a similar issue.

Large items – any items not easily carried on board or checked – are best left at home, unless essential to your travel. Contact the airlines in advance if you are planning to carry such items; they may not be allowed otherwise. Bikes are often allowed for an extra fee if packed correctly and flights to winter resorts should be used to handling skis, but in some cases it may be easier or cheaper to rent what you need at the destination. People with unusual needs, such as musicians with large instruments, sometimes have advanced tricks to get their equipment included in the allowances, such as reserving a cabin seat for their equipment. Among other items which might need special check-in are carpets, pets, some sporting equipment, and surfboards.

If you do check the large items, there may be additional fees involved and it may be delivered to a special baggage claim area some distance from where your regular luggage appears. It may also take extra time to be ready to claim.

Weight and size limits

Carry-on luggage most anywhere: 1 piece, maximum size 20x40x55 cm (9x14x22 inches). In Europe: maximum weight 7 kg (15 lb), some airlines 12 kg (26 lb), often 20 inches length.

For checked bags, the usual weight limits are:

For international flights outside Europe 23 kg (50 lb) per piece, not to exceed 60–64 inches (1.5–1.6 meters) total for length, width and thickness (check in advance for involved airlines, on-line or by phone).
Within the U.S. and some other countries, limits are the same or similar (check in advance).
Within Europe, it's often 20 kg (44 lb), with total size varying by airline; however, checked items may be limited by the total weight of all your checked pieces rather than each piece (check in advance).
Nearly all airlines/airports have an absolute maximum weight limit for a single checked item, often 32 kg (70 lb). This is for the health and safety of the baggage handlers.

If any limit is exceeded, the airline may charge a fee. It can be based on either piece size or weight (check in advance). See Overweight luggage below.

The smaller "carry-on space" on many regional jets or prop-driven aircraft may force you to check an item (at the counter, gate or on flight ramp as you board the aircraft) that you can usually carry on board other aircraft. Most airlines don't charge for such checking. But this checking creates increased risk of theft–handlers know that most such pieces contain valuables. With those airlines that charge "extra" fees for all checked bags, total baggage costs can become punitive. If in doubt, check in-advance with your agent or airline about all flights and aircraft types on your itinerary.

Fees for checked baggage

If you're traveling domestically in the United States, keep in mind all airlines (apart from low-cost carriers JetBlue and Southwest and a few regional commuter airlines) charge, e.g., $25 for the first checked bag and $35 for the second. Originally confined to itineraries wholly within the lower 48 states, fees for each checked bag are now assessed on virtually all itineraries that do not cross an ocean: still plan on paying if you're flying to Alaska, Hawaii, Canada, Mexico, the Caribbean, Central America, some South American destinations (usually flights to "deep South America" i.e. Argentina, Brazil, and Chile get at least one bag for free.)

Elite frequent flyers are usually permitted between one and three bags free of charge, depending on airline and tier.
First and Business Class passengers may be allowed three bags for free.

Air Canada charges checked bag fees on "transborder" flights to or from the United States. Unlike US carriers, they do not assess bag fees on Canadian domestic itineraries, or flights to Mexico, the Caribbean, or other destinations in the Western Hemisphere.
Some European low cost carriers (e.g. Ryanair) have no free checked luggage allowance and charge per kilo.
On any airline, you'll be charged if your bags are overweight or oversized. Low-cost carriers in-particular often have lower limits, higher fees for overages.

Overweight luggage

For checked luggage, every kilo (or inch) over the limit may be charged some fixed fee or a percentage of the airfare. This can get very expensive. For carry-on luggage, weight is usually only checked at the check-in counter, if at all. Once you pass the check-in, you'll have to look suspiciously overweight to have your hand luggage checked.

If you know your bags will be definitely overweight but you need to take so much, consult your airline. For a price, it may offer baggage "upgrades" before arrival at the airport for less than excess-baggage fees at the airline counter. Pre-booking excess baggage online can come with discounts.

Shipping luggage

You might consider shipping luggage as cargo, also known as unaccompanied baggage. Many airports have companies that will arrange this for you, and aggregators like xsbaggage can find one for you. This has its trade-offs:

Fees can be quite high, though it is almost always cheaper than paying for excess baggage.
Your bags will be shipped separately–necessarily a few and perhaps several days earlier. Instead of claiming them at your destination airport, you'll have to arrange collection or delivery somewhere else, e.g., pre-arranged with the hotel where you'll stay. For international locations, you may also need to do customs declarations/claims for your unaccompanied bags, which can be a hassle.

Tips as you pack

Pack as much as possible in resealable plastic bags (2–5 gallon, 10–20 L, smaller for bottles of liquids) or packing cubes.

They help security inspections and repacking your luggage. And they'll protect contents if your checked luggage is exposed to the elements while waiting to be loaded or offloaded at your aircraft.
Before you seal them, thoroughly press out all air ("burp them"); otherwise, at altitude the bags will burst.
They are equally useful returning, plus they can keep soiled items separate from other content.
Use burped and sealed, resealable gallon, liter or quart-size bags for bottled liquids in-case bottles leak during flight.
Compression bags may also be used for clothes, but they don't reduce weight, so they may encourage overpacking; also they may wrinkle the clothes inside.

Rolling clothes instead of folding them can reduce creases, save space and make it easier to find particular items, though clothes made of stiffer materials (e.g. jeans) should still be folded. Small foldable items (e.g. socks and underwear) can be placed in hats and shoes.

Place heavy items (e.g. shoes) toward the bottom of any rolling case (i.e. near the wheels), to avoid contents shifting around and for better weight distribution. Place heavy items in separate bags from anything fragile. Any content likely to trigger a manual inspection should be placed where it will be quickly seen as the bag is opened.

For significant liquid quantities in your checked luggage (e.g., shampoo), choose rugged screw-capped bottles with tops not designed to pop open–even if you must buy them separately and manually fill them at home. Otherwise, use new/unopened bottles of product still sealed, and tape any pop-open cap tightly to the rest of the container as well as the opening. Then put each such bottle in a separate, burped and sealed plastic bag to protect other luggage contents. If you are weight-constrained and can conveniently purchase such items at your destination, consider buying them there rather than packing them.

If you've noticed how bags oftentimes are handled loading or unloading your plane or if you can imagine what may happen to luggage when flying through turbulence, you understand why glass containers or any other fragile stuff has to be packed very well. If possible, put them individually in plastic bags and seal those with a tight knot or their "zip-lock". Then wrap them in clothes or towels and place them in the middle of your checked bag "muffled" with more soft stuff. Don't leave the bag only loosely-packed; this will allow stuff to move around inside your bag — heavy and hard objects inside the bag may hit the fragile object, and your fragile object may move towards a wall of the bag where it might land hard when dropped or thrown around.

Never put any unprocessed camera film in checked luggage, and ask security to get it hand-checked if possible. The high-dose X-rays used in scanning can permanently damage or destroy them. Color film is more adversely affected, as well as film with high ISO values (especially above 800). Protective bags can reduce the risk, but they cannot eliminate it. Video cameras that record on magnetic tape may be affected by repeated exposure to such X-rays, though not usually memory cards or processed film.

Preventing and recovering lost baggage

Place identification on both the outside and the inside of your bag.

Rugged, well-attached luggage tags are crucial–with at least name, address, phone. Those that have a flap to cover your identity are preferred to prevent others from noting your data.
Copies of your trip itinerary inside and in an outside pocket can be equally useful. Pertinent information should include: name, telephone number, e-mail address, flight number(s) and date(s) you are traveling, point of departure, aircraft/airline(s) used, and your itinerary. Airlines or others must have this to locate you or forward your luggage if your tag or the airline tag comes off (called a "tag off") or the luggage gets misrouted.
If packing a box, put your name, e-mail address and phone number(s) in big block letters and numbers on at least 2 opposite sides, plus a full itinerary sheet inside. Do not use a return address unless you are shipping something as air freight. Checked luggage should have only ONE address.
Remove all bag tags and labels attached by airlines for previous flights. Bar codes on those labels or tags can sometimes confuse automated sorting machinery and send your bags to the wrong airport.

If an airline "loses" bags, it will often lose just one of yours rather than all (except for major delays and flight cancellations). So distribute clothes and other necessaries for everyone in your group among all the bags you check. That way, all will have something to use until the "lost" bag is found. Delayed baggage coming in on a later flight is far more common than truly "lost" baggage (over 24 hrs) If possible, take a color photo of all your checked baggage, so you won't have to verbally describe it. This can be especially important where language barriers are a problem. Lost or delayed luggage is more common if you depart from a larger airport than a smaller one. This includes transfers en route; the size of your arrival airport is less important. Non-stop flights also help minimize the chance of luggage hassles, because checked luggage does not have to be transferred to another plane.

If your luggage doesn't come out at baggage claim, file a report before you leave the airport. The office for reporting lost baggage is usually in the baggage claim area. Airlines are usually able to recover lost bags and ship them to their owners.
As a last resort, airlines can search a worldwide database of the contents of bags that have been misdirected–based on passenger declarations of contents at lost-luggage offices. They do not catalog each item inside a bag, so declare one unique, easily-seen item in your bag to help the airline find it. Lost luggage will be available for about 1–3 months, after which they may be destroyed or put up for sale. All the more reason to place copies of your itinerary inside and outside your checked bags.

You should reinforce your to-be-checked luggage so it won't break open due to rough handling. Two ways include:

Tightly applying brightly-colored luggage straps. Ensure any strap-ends are well-secured/tucked-in so they won't be snagged in handling. The colors will help you find your checked bags at baggage claim. Otherwise, consider customizing the outside of your checked luggage with brightly-colored tape, ribbons or the like, so your bags don't look the same as hundreds of others at luggage claim.
Wrapping: In major departure airports, you may find a luggage-wrapping service. For a fee, they will wrap a piece of luggage in multiple layers of clear, tough plastic sheeting. (Such wrap is not permitted if your baggage will go through U.S. and some other countries' security screening; they must be able to quickly inspect contents manually.) Wrapping occurs before you present the luggage at the airline counter to be checked. So, make sure the weight of the wrap doesn't make the item overweight. Also make sure your name tag is clearly visible–preferably outside the wrap.

If the number of your outbound checked bags doesn't reach the limit, and you know you want to purchase items before return, consider packing a collapsible bag in your checked luggage. You can then use it to pack soft items and check it for return.

In some airports, security of checked luggage has been an issue; contents have occasionally been stolen while checked bags await loading on your plane. Such thieves focus entirely on valuables, not day-to-day items. So carefully maximize what you can wisely put in checked luggage within weight and size limits, put no true valuables there, and be cautiously creative with carry-ons. (See also discussion below on securing bags.)

Securing your bags

The probability of having items stolen from your luggage is very low. But it does happen, e.g., zippers can be rapidly opened with a ball-point pen. Lost or pilfered bags can become a serious problem, especially as you begin a long or important trip. Other discussion about luggage tags & printed itineraries help avoid misrouting. A few steps can help deter damage and thieves, but can be compromised because items must be ready for security inspections.

All bags passing through airports receive either electronic or manual security inspection, sometimes both. If you're not sure about all the airports you'll use, consult your agent or airline for details. All checked bags to, from or within the US receive electronic scanning at least once. This is also common within nearly all developed countries.

If any bag needs to be manually inspected, it must be opened. If locked by other than approved locks for that country (e.g., by TSA for the U.S.), inspectors must cut or break them (and perhaps the zipper-pulls they're applied to) to get inside. If you will check hard-shelled luggage with "built-in" locks, consult the airline or your travel agent in advance for usability.

After manual inspection, bags are re-packed and re-secured by inspectors, with your lock, your luggage strap or a strong plastic tie joining the zipper-pulls, all so that later tampering remains somewhat difficult. If plastic ties have been applied, you'll need something to cut it after claiming the luggage. Put it in an outside pocket of a checked suitcase—the "rules" allow them there.
If contents were manually-inspected, you'll usually see a note inside to that effect.

You may also be directed to check one or more bags (that you expected to carry-on) at the ticket counter, aircraft gate or as you step board. Reasons can include:

You've over-packed one or more of them, or have too many. On budget and some international airlines, this can involve a major fee.
Part of your journey is on a regional jet that lacks in-cabin space to store them.
If one of the last to board, the cabin staff may realize there's no more in-cabin space available (except under the seat in front of yours, if any). They will then make the dreaded announcement–that those not yet seated must allow nearly all their carry-ons to be taken to the hold (checked); items will receive special tags. This can happen even before all the bins are full, since searching for a place for your carry-on and placing it in the bin or returning it to the front of the plane to be gate-checked at the last minute takes time, which might delay a flight by several minutes. Ask where you will pick up yours. Yet, carry-ons are much more likely to contain valuables, and so are more often targeted by thieves. You should lock them (or be ready to) anytime after passing the personal security check. If practicable, snugly apply a luggage strap to generate some complexity for thieves. You'll usually claim "checked carry-ons" at the regular baggage claim; between plane arrival and when you claim them is when most risk arises. For smaller aircraft, you may have gate- or ramp-checked your carry-on, and it may well be returned to you as you depart the aircraft.

Some travelers take extra precautions with checked bags–some expensive:

To quickly locate their bags at luggage claim, they may fasten flashers/beepers to the outside that they can trigger by a device they carry.
Others may place GPS tracking devices inside their luggage that indicate its location—helpful if lost or misrouted.

Carry-on only travel

If you need less baggage, consider taking carry-on only. This saves time at your destination because you don't have to wait to claim your checked luggage, and carry-on luggage is less prone to getting lost or stolen. Many airlines charge a fee for each checked bag, at least if you do not fly business class. Check with your airline to make sure that your bag fits within their size/weight restrictions for carry-ons, and whether your purse or laptop counts toward the limit of how many bags you can carry. Also, with tight security restrictions on what kinds of items you can take with you into the passenger compartment (particularly nothing that could be used as a weapon and liquids in anything except small bottles), a carry-on-only strategy may not be practical so it is also useful to check the airport which you will departing out of to see restrictions in addition to the ones implemented by the airline you will be using. It is worthwhile to carry all critical items in the carry-on luggage, such as underwear, extra clothes, toothbrush etc.

If you want to travel with carry-on only but also have luggage that should be checked-in, you can use a company that provides a luggage delivery service. Alternatively, you can use a wardrobe management company that not only stores and ships your luggage belongings, but provides you with a database to 'virtually pack' your items, and cleans them for you between trips. You can even arrange to have clean pressed apparel awaiting your arrival.