Good work on the structure and shape, I just tweaked it ever so slightly. I would say don't be afraid of darker shadows, the only other thing I've done to this illustration, is adding a multiply layer on top. Really thinking about the structure of the face and where the light is coming from. A simple shadow layer can add a lot of three-dimensionality to your paintings. Study the skull and adding light to simpler 3D shapes (Spheres, cubes, etc.). Talk to yourself while you do the painting about your choices while painting. Great work keep going!

