I use Imperial fist contrast over Zandri Dust primer, some shading with thinned down Magmadroth Flame contrast. Then an agrrax Earthshade wash, with Balor brown and Flashgitz yellow highlights.
Thank you!! Sure: mournfang brown, cyborg brown contrast over that. Then bring up highlights with 50 / 50 of each, ending gradually with pure mournfang brown top highlights.