A few quick tips I can give... You're lighting really needs some work. Good lighting can really add a whole new dimension to your work. Think about sharpening the focal point a bit to help it stand out, and also blurring the background a bit. You've got some really awkward effects and textures going on in here like those purple dots floating around.

I'd say do a little bit of brain storming before you go into the sig. Good luck!