Well the most important thing in this shot and in all of photography is lighting. I used two speedlight flashes that are placed camera left and right to get the lighting correct. This was just shot on my couch at home and normally I use the light coming from the outside window placed just behind the couch, but in this shot I covered it with a black sheet. That is the foundation and the most important part, tru there is a lot of pp, but if oyu don't start with the correct foundation you won't get the desired effect. As far as ps goes, man where should I begin? I have been working on this effect for months and I have done so many things that I had to make actions. Here are the main things I do, tweak levels, curves, selective color, tons of skin retouching, black sketch with gaussian blur behind the image then I play with the opacity. I play with the local contrast, shadow/highlight, unsharp mask, etc.... I really don't have specifics because each one is a little different. This may sound like a lot, but I have gotten very fast with my workflow. Thanks for the intrest.