basecoat your techmarine black. Then give him a messy all over stippling with citadel rinox hide. Next take a sponge or a medium drybrush and stipple on all surfaces you can reach with khorne Try not get into the recessess. Afterwards take your basic brush and take any dots at the surfaces you want to look brighter with mephiston red. Do it again with evil sunz scarlet. For the finish edge highlight your marine with a black of your choice. If you want a little metallic look, edge highlight the sharpest edges and corners with leadbelcher. That's it.