I'd work on getting your render to blend better with the sig. So I would take away that white brush around her or possibly set it to linear dodge or somthing because right know the render and background don't go well together
Not only the smudge brush that can help sometimes. look here (may need to create an account) http://planetrenders.net/forums/ lots of those tutorials will help you out
It's a nice one. Work on the blending on the render better with the background and effects, and text. Otherwise you're getting the basics down nicely.