I'm really happy with the way this turned out. I could have spent more time on it (:'D the background took like 3 minutes to make), but I like all the flat colors.
I used a picture of Gwyneth Paltrow (because when I read the books, I imagined the Gwyneth as the witch, almost exactly like this, except with a cool little crown.) and basicly just embelished the dress and changed her hair. But I pretty much drew this all freehand in Photoshop, so that gives me a warm feeling inside. :)