Evaluate what kind of surface you do most of your running on. Not all shoes are created equal and the terrain that you run on can make a big difference in their comfortability and performance. There is a lot of information on soles, insoles, inserts, and other aspects of a shoe, as well as how these characteristics improve your walking and running. Consider whether or not you run on hard or soft surfaces, pavement or dirt/grass, indoors or outdoors. All of these factors play a big role in picking out a new pair of running shoes.