Cookware sets tend to include a stock pot, saucepans, and frying pans. But some pieces may not get as much use as others—or you may not use them at all. So is it worthwhile to buy a full set?

Sure, you can stir-fry in a skillet, but a wok is a better choice: With its high sides, a wok holds more and you can move the food around faster to keep it from becoming overdone. These pans are ...