Cheers Jay Thats a great Idea. I haven't really done a breakdown of my 2D work.

About that last image. The small scale doesn't do it justice. The original is quite large. The best example of how I did it was the same way I did the Kate Beckinsale sketch( Large scale ). I start with line art to get all the basic anatomy down. I can either do this freehanded on paper, or with photoshop. Once the line art is complete and checked for accuracy with the refference I start shading and matching gradients with the refference. This the most time consuming part. The texture comes last. If I cant get the texture I want with a pencil or brush, I will make a texture. Something that makes it "POP". This is where Mayaniac thinks I'm cheating and not actually drawing the work. That magical filter he thinks exist's in photoshop.

Once the whole foundation is complete I will move on to the color, the easier part. What I'm doing is converting black and white to color. It's all done with masks. A 3 layer mask to be exact. Found the technique on a tutorial from photographers web site. I will try to find the address and post it here.

Here is a example with a real photograph. The original black and white had to be color corrected to bring back the proper gray scale info. The color is still somewhat flat but I consider it finished because it was just a learning experience. I apply this same technique to a black and white sketch. I am still working with different techniques but this method has proven the best so far.

BTW, the original black and white photo is from the tutorial I found.