This is taken from the "How I Paint Things" chap on youtube. Really heavily drybrush the Eldar Flesh and then throw Carroburg Crimson on quite thick. After this the marine will look like red wine, it is lovely.
Blah blah bolters, etc. However, also paint the chest eagle black and then drybrush it with Longbeard Grey; it will come up like stone. Rhinox Hide goes on the bag and belt.
Simple base layer of Rakarth Flesh and then just lay Ushabti Bone on top. Could probably suffer some recess shading but not worked out what looks best yet.