Been awhile but I just made up a set of desert terrain for all periods. First is a small compound suitable for an outpost or small village. It has several buildings and a small low wall for defense.
I shot this under the blazing sun to give it the hot,dusty effect common in this climate.The next photograph is shot in shade to show off the detail more clearly.
My next set is of rough terrain used to represent rocky outcroppings which is bad going for vehicles,cavalry etc. Again I shot the terrain in hot light and shade to show the details.
Finally The Oasis of ever-flowing water said to be made from the tears of the Mighty Arff when he saw the were no more worlds to conquer. The water is clear colored resin with the edge of the Oasis containing some grass and wet sand alongside the edges. I used a technique to give the pool a sense of depth to the viewer. I again shot hot and shady to show off detail.
Last but not least, Palm trees these are really inexpensive and easily obtainable from local shops. It takes a little prep and ingenuity but one can make some passable palm trees in about 2 hours.