Nobody has mentioned this yet.... my husband digs a little hole in the ground for the wheel that is too high and drives into it.
We aren't talking much of a hole and it is usually in a sandy soil that is easy to put back when you leave. Rather than spend lots of time with the levelers, he gets the sides level, then adjusts the hitch up or down. We attached stick-on levelers to the bumper and the hitch when the trailer was perfectly level in our driveway.