I saved it in stages so that you and I can see the progress.
I always like seeing stuff like this from concept to creation...
Here is my initial sketch, very loose and fast, all I knew at this point was that I wanted this to be a desert environment
I decided early on that I wanted to have a strong light coming in from behind the view and to the left.
I was still relying on the linework at this point to define forms
After I was somewhat satisfied with the look I pasted the painting above the linework.
I then just kept on sharpening edges and pushing the contrast in the forground and midground until everything looked sharp enough to be finished.