Heres another image created in a similar fashion to the door with one exception. I went into Color Efex Pro and added a vignette. I enlarged the vignette to include most of the image. Due to the edges being mostly white and blending with the backround I added a thin border.
Dave, this is another good one! I do think the skull could have a little more sharpness to it and the vignette at the bottom is pretty close to the bottom of the skull...if you have a little more room it might be worth adding it there to give a little more separation between the skull and the frame.