Erf ... Technical masturbation. But I've got a funny idea for the final picture ;)
Some few tricks:
- Always do different layers for each parts (eyes, mouth, skin ...).
- To see if your luminosity and your contrast are good, desaturate your picture and your photo ref.
- Incrustation and colour type layers are very useful for minor changes on your tones
- The "dry brush" ("pinceau à sec" in french, I'm not sure of the translation) is very useful for the skin texture.
8 hrs T_____________T
Next step : the breast ^o^