Check the fit. When the shoe is on your foot, you should be able to freely wiggle your toes. Make sure you can fit at least one thumb between your longest toe and the end of the shoe's toe box. The shoes should be comfortable as soon as you try them on. Don't plan on them fitting better after "breaking them in."

“Comfortable everyday sneakers will have a cushioned midsole and insole, a stable heel counter, appropriate arch and forefoot (metatarsal pad) support, and adequate traction on the outsole,” he says.