Yeah, you just bend a few walls out of the ground and voila, earth tent.

You haven't heard of probending? How---oh...right, I guess I am pretty far from home. [He clears his throat.] Probending is a team sport. There benders of earth, water, and fire are on each team and try to knock each other out of the ring using their element. There are some other rules of course, but that's the gist of it.