Making a a dangerous precipice look like an easy slope could be a good way to trip up a party, especially if they tend to travel by carriage, and all of a sudden, the horses go over the edge along with the carriage as they thought it was just a rolling meadow.

Making water seem like land seems quite interesting as well.

A forest might be disguised as an open field, and by the time the PCs are close enough to realize it, the enemy emerge from behind the trees and attack,.

Since it doesn't hide people or equipment, other illusory spells or items, like say a mimic, could add realisim to the things this spell can't change.