Photoshop work done...
1. The face was masked out on a new layer using the lasso tool, eyes and mouth were punched out as well as anything else that wouldn't recieve a color change treatment. In essence you should be left with a mask that looks much like a theater mask.
2. Multiple layers were created of the cut out face, each layer had a different tones of red or orange. To achieve the tonal changes on each layer use the Color/Hue/Saturation dialogue (ctrl+U). Then each layer was blended into the one below with the earse tool and layer opacity controls. This will let you tweak what colors you want.
3. The face layers were then compressed into one final layer and a duplicate was made as a backup. Working on the master layer use the 'liquify' filter to lift and stretch certain areas of the face (in this case to raise the eyebrows and point the ears).
4. Once you have the face edited to achieve your look its time for the texture treatment. In this case I used a reptile skin shot using a single light source. I then adjusted the darkness and highlights a bit to exagerate the black and cause some blowout in the highlights. Once I had the skin to my liking I made multiple layers and each layer was shaped, turned and transformed onto its area of the face to match the lighting. In some cases you may want to use the liquify filter on individual peices of the reptile texture to match certain contours on the face.
5. Finaly each reptile texture layer was set to "soft light" and the opacity was tweaked untill the texture was pleasing. In some cases I went back and further tweaked some of the textures highlights.
I hope this helps you guys play around...