This image is another one submitted on the the Model Mayhem website for retouching. The photographer in this case was Dallas J Logan, from Brooklyn in NYC. Most of the retouching on the skin was achieved by painting with a small low opacity brush (4-7%) set to either black (burn) or white (dodge) on a 50% gray layer set to the soft light blending mode. The clone stamp and healing brush were used sparingly on the the skin, apart from removing or reducing some of the major blemishes, but quite a bit on the hair.
Cheers
Colin