Use the path tool to make hair if you don't have a tablet or something else, sometimes i like to take the polygonal lasso tool and make the base of the hair from there then take the path tool and curve the lines, makes it allot easier for me, also it looks like you need the toribash gimp color palette, that way you can sell/make/use heads that you make to match with your force/relax.
Anyways for a beginner this is not bad, minimal mapping problems on the eyes, the whole head could be raised a bit and the color combination could have been way better.
6/10