Duplicate layers at varying transparency, image adjust brightness contrast, smudge tool, eraser, overlay, blend, and maybe a little accented edges filter, gaussian blur and noise, flatten. you figure out what order and how much... I've been using photoshop for so many years that anything I do in it is second nature. That's not to say I'm any kind of "pro" at it, but I've developed a familiarity with it.

Postwork took about 10 minutes, I usually go a little more artificial looking. I really like the look of some vexel art I've been seeing lately, next thing to tackle I guess... on top of this stuff.

Oh, BTW... Look at some of Fabiana's renders. She's probably one of my favorites on the whole site. Totally beautiful!