Probably one of the most difficult things I've had to pull off in area design so far is the generic random desert area. There's only so much that can be done with sand y'know. Although I have been fortunate in some texture/color experimentation to break up the monotony. A Joshua tree here, some aloe there, a few rocks scattered around.
The challenge is keeping things looking like a desert without making the edge of the area inviting to prevent players from hitting the invisible wall. I'll only have a few of these areas that will mainly be used for transition/travel, but I still want to spend the time it takes to make them look just right.
Sands of Solvheil Series
Design Document for Sands of Solvheil I: The Ruins of Kazatharis
Design Document for Sands of Solvheil II: Beneath the Hearleforne
Design Document for Sands of Solvheil III: Crusaders of Shalihir