Note that this may be the same as Duncan Rhodes' desert basing style. I am no longer subscribed to his Painting Academy, and had this written down in my notebook by hand, so cannot check - credit to him if that is this case.
Use Neutral Texture for Rough Terrain across the base.
Basecoat Balor Brown
Wash Reikland Fleshshade
Drybrush Zamesi Desert
Drybrush Screaming Skull
Rim base in a neutral tone like Corvus Black or Steel Legion Drab