Have you ever got stuck with a noobie made render?
Here is How you make your own.
Step1
pen up your favourite IMG, use one with good quality beacuse we are going to zoom in, ALOT, and it migth be hard to see if you have poor quality IMG's.
Try not to use one where the Character/Object get affected with ligths you dont whant to include in your render.
My render will show you just how awful that looks.

Here he is, Beautiful preview of the t5 wow armor (dosnt matter if you play wow its just a guy in a armor that looks cool)
Step2: Now lets get to work, select the Quick Mask tool in the toolbar

And start painting the render with a black brush, be sure you have 100% opacity or you will get troubles.
I used a 16px large brush and 75-80hardness.
Draw the basic outline of your render and leave tricky areas (no need to waste time on resizing your brush)
Remember to zoom in, alot. this REALY help you out.

Step3
aint small areas at a time, dont rush it. And when you get to tiny parts, use the Polygonal Lasso Tool (L) This takes care of all the details.
Tip:When rendering a large photo, use feather of 1 or 2 and select at the 1st pixel at the model. (i know this can be hard to get but once you got it the result is stunning)
Step4:Allmost done, now finalize your render and take a closer lokk at details.

Step5:Now its time to make this red paint an selection, press the button left to the one you pressed before you started painting.

OK what you have now is a selection around, your whole canvas
we dont whant that!
BUT easy fix
Go to Select->Invert and you are ready to Ctrl+c,Ctrl+V ^^
And this is what i got

Note1: See that wasnt so hard, take a look at the legs, thats how it SHALL NOT LOOK, if you experiment with the colors and ligth with this image your are going to have a problem. Now you underrstand why you shall use renders that dont recive ligth on the actual char/object.
Sorry if the render wasn't 100% but i kinda rushed this just to give you an idea of how you shall procced with this kind of problems.
Hope you all a fun time here at CrystalXP, Btw, check out my Tuxes at the gallery 
Note2:This tutorial was originaly maid by me, i have not used another tutorial to make this, this stufff is from my own head, if someone uses this method and call it theirs its not!
Dont steal or copy any of my text.
I have posted this tutorial on other grapics forums before so the initial copy rigth is at 2001
Copyrigth Rasmus Bremholm 2006