Mech Police

Wanted to learn couple of new techniques about concept art, where i make a hybrid between 3D sculpt and Photoshop. I sculpted first a mech in Zbrush, and rendered out several passes as used blending mode and draw on top of it, and this is the result I got :)
I wanted to learn more about photoshop and how i can use it in my workflow. I used between 45 and 60 min on the sculpt as I had no idea what to create and as I don't have any experience with mech sculpting.

However, got really satisfied with the result and want to continue this workflow! :)