Are you saying you did this with a mouse? If so, that's impressive! And yes, a tablet is a HUGE help. As for feedback, the hair looks good, but the lighting looks a little flat. I think if you went for more dramatic lighting, you'd achieve more depth in the painting. Just imagine you have two or three light sources -- maybe a warm key light, a cool rim light, and then a filler light. You might need to use photo references to get the shadows right, but really, lighting's the best feedback I can give on this piece. It'll add realism to the skin tone. Hope that helps. :)