Thanks for the tip, davetwo,
http://psd.tutsplus.com/tutorials/photo-effects-tutorials/split-freque ncy-healing/
This tutorial is a good example of how shocking it can be to become aware of how much extensive retouching is done to shots of high-fashion models before we see the final published images. Might as well use paintings instead.
Very sobering, and very comforting when appreciating live women in real life.