1) A can of the cheapest available flat black
2) A can of Rustoleum Desert Bisque
3) Cheap hobby acrylics from Walmart:
a) Raw Seinna
b) Burnt Umber
c) Bright white
--Paint the whole thing flat black. Don't be afraid.
--Dust fairly heavily with the Desert Bisque. Spray from the top so that the black base pokes through in the places where shadows should be.
--Drybrush moderately with the Raw Sienna and Burnt Umber
--Drybrush lightly with the Bright White to simulate the glint of sunlight. Don't overdo it.