Well, it's pretty cool but, if you make it on the hair, not on the skin (the black shades), its look will be like the skin/face giving shadow to the hair, not the hair giving shadow to the skin/face. If you want, you can change the black to another color, or erase it, and make the black shades on the skin, so it will be like a real shadow. ;)
And probably you should make the bottom side of the hair to be closer to each other side, if you know what i mean...