Before I start going into design choices for a desert, I would like to address this: The default Instrumentality sand carries far too much contrast and it does not contribute to the feeling that sand is supposed to have as a result. It would be better if it wasn't 8-bit into CSet 1 colors.
The main defining feature of a desert is that there is very little life and therefore shouldn't be busy - Go easy on the details but place them with careful consideration to the overall layout of the screen and to the atmosphere you want this particular area in your desert to have. Oases, wherever they are formed as the result of a lake being at the surface of a desert or formed just after heavy rain, are the exception and should be more busy.
One major pitfall I see in deserts in quests that makes them repetitive is that people seem to neglect to add in details that make these screens memorable - In way too many quests the desert screens just feel bland and lifeless and/or lazily designed. Going the complete opposite way around and cramming them with details makes the screens feel a lot more interesting, but the resulting desert just doesn't feel like a desert. Strike a balance between the two extremes and make sure that you take care in making each screen memorable, giving the desert the atmosphere you want it to have and telling the story you want it to tell (remember, the written word isn't the only way to convey a story!) and you should be on your way to making good deserts.