What types of trips do you take most often? This is an important consideration. If you just take weekend trips, all you'll probably ever need is a 19-inch carry-on. If you take business trips that last several days, you'll want a slightly larger bag that allows you to pack a mix of professional and leisure gear. If you're the adventurous type, a heavy-duty bag that can hold your sports gear is a must. If you only travel a couple of times a year, but it's a mix of short and long distances, a luggage set may be your best bet.
What type of aircraft are you flying on? You may think your carry-on bag fits your airlines carry-on size restrictions, but that depends upon what type of plane they put you on. If you end up on a regional jet, you'll probably have to check anything longer than 19 inches. And the chances of that happening are very good. More than half of all passenger flights are now completed by regional carriers, even on flights as long as four hours.
Can you lift your bag? Do not rely on the kindness of strangers. If you can't wrangle your own bag -- which means lifting it in and out of the overhead bin -- without assistance and without clonking anyone on the head, either check it or pack a smaller bag.
How much do you pack? Most airlines charge baggage fees by the bag, so it's usually better to opt for one large checked bag instead of two smaller ones. The exception to this is if your bag goes over the usual checked bag weight allowance (typically 50 pounds for domestic flights) or exceeds the airline's size restrictions. This will incur extra charges. Checking a second, smaller bag might be cheaper than paying extra fees for an oversize or overweight bag.
Can you try before you buy? We strongly recommend not purchasing a suitcase sight unseen. Most of the bags we review can be found at your local department store, sporting goods store or luggage store. This is particularly important since manufacturer's warranties also don't cover choosing the wrong bag. If you buy it, you may be stuck with it. Checking it out in person beforehand might reduce buyer's remorse afterwards.
Warranty, schmarranty? Ah, the 10-year luggage warranty. There are few "guarantees" more misleading, and reading the list of restrictions is about as sobering as listening to the possible side-effects of the latest pharmaceutical. They don't cover normal wear and tear, misuse, carrying unusual items, accidents, exposure to weather, scratches, dents, water damage or damage by the airlines. In other words, they don't cover the things that actually break a suitcase. The only thing they cover is manufacturer's defects, but no manufacture really defines exactly what that means. There are a couple of exceptions, such as Briggs & Riley and their "Simple As That" Lifetime Warranty that even covers airline damage and is held up as the industry standard. With most others, it's not even worth the hassle to try. Just buy a new suitcase.
Southwest is the last of the airlines to give you a free ride where baggage is concerned -- they allow you to check up to two bags at no charge. But checked bag fees aren't the whole story. Some airlines are now charging for carry-ons. Many airlines also charge you a fee for making reservations by phone, seat selection fees (which you need to keep in mind if you're traveling with children and want to be sure you sit with them), and steep fees for any ticket changes. Always double check your carrier's site for the most up-to-date information.
One way to get some of those fees waived is to stick with one airline. Most offer frequent flyer or loyalty programs that give your first checked bag free, waive ticketing fees, and offer priority boarding or other discounts. The best of the loyalty programs are usually tied to a specific credit card that has the airline's logo. The more you spend, the more points and perks you can earn. NerdWallet.com offers this comprehensive chart of the available travel-related credit cards and the perks they offer.
However, if you don't fly enough to make it worth your while to tie your spending to your travel, there are still ways to save money when flying. Good planning and learning how to pack smart can greatly reduce the amount of space you need, which may allow you to downsize to a carry-on sized suitcase.
Start by checking the weather where you're going. That will help you decide what type of clothing you need. Pare it down to the bare minimum. Then, learn to pack your suitcase to maximize its space. SmartPacking.com has a plethora of useful tips for packing light. We're also fans of learning from flight attendants, who are professional packers, like this slide show from the New York Times that demonstrates how to pack for 10 days in a carry-on. If you need more tips, just Google, "packing like a flight attendant." You'll be amazed at how helpful that can be.