The first thing to consider when shopping for new luggage is the best size for your needs. Baggage policies vary by airline, so what you can carry on with one may need to be checked with another. To help prevent complications later, check the website for the airline you plan to fly on and familiarize yourself with their baggage policy. You don't want to add to your stress by learning at the airport that you can't take your new carry-on with you on the plane.
While knowing the airline's requirements are important, so are knowing your own. Do you need multiple bags or just one that you can fit everything into? To visualize just how much you need, set out everything that you would take on your trip. It's easy to underestimate what you will need, so this helps prevent you from doing so.
The weight of your luggage is also very important. Depending on which airline you fly with, you will be charged a fee if your baggage weighs over a certain amount. Therefore, you want your luggage itself to be as light as possible to allow you to pack more into it. It's easy to find lightweight suitcases these days, and even when shopping online, you can easily find luggage weight listed.
What material would you rather your luggage be made from? Soft luggage, made from nylon, can be crammed into a tight space to make it fit. Hardside luggage will protect your valuables with its Polycarbonate construction. But the hard case keeps it from being shoved into a space smaller than itself.
Finally, make sure you don't skimp on quality when buying new luggage. A good, sturdy suitcase will give you peace of mind when you travel with it. Stick with the popular brands. Also pay attention to the warranty. If the manufacturer believes in the product, it will offer a good warranty. Be careful when looking at designer luggage -- it doesn't necessarily mean it's good quality. While it's pretty, it's not usually designed to last. To learn about how well a suitcase you want performs under travel conditions, check online luggage reviews.