You'll find as many methods as there are people who cook out. When you put them in foil or in their shucks, you're steaming them over coals/flame. My husband prefers it when I do like I do with other veggies -- shuck, then brush or roll in olive oil and seasonings, then put over the flame. It's more roasted than steamed. All are delicious, to me there is no wrong or right, just what you like. He just happens to like it roasted. As for me, I've met few ears of corn I didn't like, and the way he likes it is easy on me, since I always put a ton of veggies on any time we light the coals.