I basically used acrylic paints! Cheap ones work, too. I mixed white/grey/green/wheat yellow altogether for a base skin coat & added about 2 layers until it was fully opaque.
I then worked on the face details, THEN stippled the green moss for the very last, and even into his hair! You can seal with a flat Mod Podge after, and use gloss Mod Podge (or other brands that basically say decoupage) on the eyes/lips/nails. If you want shadow detail, water down an acrylic. Do to the shadow detail, like around his nose and cheekbones before you work on the face details (like eyes/lips) Have fun!