A few airlines still don't charge for checked bags. If the ticket price for those carriers is comparable to what you were planning to spend, it may be worth flying those airlines to avoid the baggage fees. Some airlines also allow you to purchase benefits when you buy your ticket. For an extra fee, you can get a package with free checked bags, early boarding and seats with extra legroom. Just remember to check with the airline before you fly for the current information on baggage limits for your flight. If you are taking two bags, be sure to look at the cost of both your first and second bags.
The majority of airlines still do not charge for carry-ons. Most of them allow you to bring one small suitcase and one smaller bag onto the plane with you. The standard for a piece of carry-on luggage is that it cannot be more than 45" total when you add together the length, width and height. The second item can be a pocketbook, laptop bag, briefcase or similarly sized item. Even if you are checking luggage, keep heavier things in your carry-on to avoid hefty surcharges for overweight checked bags.
If you fly regularly, consider flying with one airline, or at least the same alliance. By flying 25,000 miles or more per year on American Airlines, for example, you will achieve gold status and be able to check bags for free on that airline as well as any of its One World partners. You can also earn elite status -- or even get free bags without it -- with some airline credit cards.
If you can pack in advance, it could be cheaper to ship your luggage to your destination instead of paying airline luggage surcharges. If you do check your bags, some airlines will take a few dollars off the fee if you pay the baggage fee online rather than at the airport. Also keep in mind that airlines do not charge first-class passengers for bags -- check to see if you can upgrade your flight with miles.