Den's Graphics

On both, the background is very plain. Also, your render has some horrible jagged edges. It's almost as if you used the magic wand tool to clear the render out. I would sugest that you use the polygonal lazo tool, and get a marquee around your render on a click by click mode. it is extremely boring, and not really efficient, but the result is a whooole lot better. My avatar and sig were both cleaned this way.
And so is this one. You can zoom in very closely and you will see clean edges between my render and my background
https://img.photobucket.com/albums/v168/raconmario/gundam2.png

What I found useful when I was starting out, was to look at some tuts, find out how to do a technique from them and experiment with it until you get something you like. I did this a lot and now I know how Photoshop works alot more and how to do stuff with it.

Oh right.
Another thing you can do is go to Edit>Image size, and change the resolution from 72 pixes (or DPI) to 180 or something a bit higer, THEN shrink down the image. It gives you a bit better quality and not as bad pixelating.

here is my latest project:

Not bad. Background is a little better, although your character render looks a bit odd. I like it though.

I'd play with the blend modes of your render a bit, try to make it stand out a wee bit more. But maybe you were aiming for a camo feel, which works fine like that.

You're improving that's for sure. One thing I noticed is on the words Call of Duty there are a couple of bits where some of the letter has been cut off like on the end of the C and a little on the side of the T.

Popper quality render at last! \o/
I like the Halo one.

Thanks for the offer, but I'm quite fine with my Shana one <3 (Have you ever tried clicking it?)

I love the first one, if it was only bigger...

Sure dude, that would be awesome. Love you long time.