None to shabby for a first attempt.
It needs some depth, so blur some of the background a bit. Also, there is no flow with the render, so it won't look as together as it could if you say, copied the visible image, colourised, and set to Overlay, or perhaps even gradient maps at about 10-20% opacity.
That was all Gimp related talk btw, no clue when it comes to CS5.