Jonathan Hamilton – Here is an artist that has a unique look to his characters in which you are able to tell Jonathan created this one. It’s that personal style that many artists long for and his tutorial covers the foundations of the process to create something wonderful. He has a few step by steps on his site that I recommend checking out! He has a fantastic tutorial explaining AO, so check it out and read his tips on the steps along the way!

Ambient occlusion (AO) is best described as the soft, subtle shadowing that appears between close objects and other tight spaces where light can’t easily reach. When emphasized in the painting process, AO gives art a very distinct look — almost like a computer-generated 3D model.
Home Page -

https://cgcookie.com/tutorial/painting-with-ambient-occlusion/