After a long delay, I'm going to finish this project :)
I've decided to make a simple desert base, using picture frame, isolation foam, some wood laths for the sides, DAS modelling clay, rocks etc.
Starting with the picture frame-it's simple, you have to glue the back to the frame with white glue and remove the glass. Then filling the main space with isolation foam and adding wood frame to the sides. My foam wasn't thick enough, so I filled the top with cork sheet. Some slight rising on the terrain are added.
Next I made the terrain using modelling clay. It's easy to work with, only thin layers are needed.
Adding some various sized rocks, some sand etc., and printing the tracks.
The base is primed with Vallejo polyurethane primer.
Sides are primed with black.
I mixed several light colors for the sandy color of the terrain.
Brush painting of the rocks.
Adding a thin wash and placing some dry tufts of grass randomly.
Overall airbrushing with Africa dust effects, not too heavy, and pigments here and there.