see the sbs

I would suggest getting rid of the outer glow on the horse. Shadows work wonders.
Edit: Looks good

Always try to include a hi res image.

The unicorn doesn't blend in. Good try though.

To get rid of a white line like around the legs in your image: if you have it on a separate layer, select the area outside the legs w/ the magic wand tool, expand the selection by 1 pixel, feather 1 pixel, and delete. You may have to repeat if it's still obvious.

Can't see the hat. Try to remove the lines around the ring.

Look at your floor source. See how it's darker back in the corner & gets lighter in the foreground? That's what your floor should do. Once you've done that you can make your reflections a bit brighter. GL author.