Prime the model either black or grey.
Basecoat Dheneb stone.
Wash with Gryphonnie Sepia
Recoat with Bleached Bone leaving the washed colour in the recesses.
Highlight with a Bleached Bone : Skull White mix of 1:1
Further highlight if you want.
Alternatively you could use Bronze flesh as a basecoat instead of the dheneb stone and wash, but i prefer that colour more.