Portrait practice (help needed)

Wow this is pretty impressive! The only thing that I may suggest is perhaps form the nose and the mouth a bit more like how you did with the eyes because when I look at this piece the thing that my eyes are drawn to is the eye brows(maybe lighten the eyebrows) and the eyes but all of her other features are a bit lost :c Also maybe define her jaw line a bit more with a lighter shade because it looks like it's getting lost into the neck and the hair layout. I'm not a digital painter, but maybe for the hair you could find one of those texture brushes on photoshop and take different shades of black/brown and maybe go in a loose, circular motion(if that makes sense) and do a different color for each layer and it'll eventually look like crazy curly hair and you don't need to worry so much about the shading since you already did that with the layers Can't wait to see the finished one and I hope I helped a bit >.< Very well done