laughing queen

This is a portrait of a friend of mine from school. Sadly we don't see a lot of each other lately, since I moved away to study in a different city.
I used a B and a 3B pencil for this, it took me about 9-12 hours over a period of three days (time which I SHOULD have spent studying...)
I darkened it a bit in Photoshop because the scanne swallowed all the shading in the face... anyways, hope you like it, critic and comments very welcome, since I still hope to improve

Oh, almost forgot: thanks a million to =akaLilith for her awesome tutorial on hair [link] which helped me a lot with this portrait!

Edit, Description on #GimmeFeedback : This portrait is finished and I'm probably not gonna work on it any further, but I would appreciate any comment on how to improve and what to do better next time, since I plan to do more portraits. How can I make it look more realistic? Are there any flaws or mistakes I should avoid in future? And btw, are there any tutorials on how to find fitting keywords?