Nice first try mate.
I'm no expert but i have dabbled in PS a few times before so i'm gonna be honest here ... the render isn't very well cut out. Thats why there is that uneven white line all round it.
You could try zooming in and erasing the outline. Or selecting it and "feathering" the edges. Also you could make "duplicate" copies and set them over each other with different layer properties like luminosity. soft light, overlay etc. Experimentation is the key here as you can always "undo" what ever it is if you don't like it.
But all in all a very good first try.