Make sure the legs and the pieces holding the legs together are sturdy.
Sit in and try some out. (e.g., Dick’s Sporting Goods, Sports Authority, REI, Walmart, Gander Mountain, Cabellas, Campmor)
Don’t go Cheap! Spend the extra $15 on a chair that will be more comfortable and durable for years to come. Sure that $10 chair at the supermarket looks like a great deal now, but it’ll be in the garbage by the end of summer.