I wanted soft and lateral lighting; it is called "low key" lightning. I think this kind of lightning gives great result for portraits. It also highlights the skin texture. Here is a little sample of all the reference pictures/inspiration photos that I used (Fig.12).
Before deciding on the lighting, I created a quick skeleton to create different poses. I made some render tests with a lambert and geometry hair that would give me a rough idea. For each one I made different lighting set ups (Fig.13).
I wasn't sure which one was the best, so I chose several configurations and went ahead with those. I put each configuration in a different frame, so it was easy to change from one to another. For all the configurations, I used only one area light that changed its position (Fig.14).
I used an SSS mental ray shaders with the textures. The epidermal and subdermal textures are variations of the original one (Fig.15).
I broke down the shader and composed all the layers in Photoshop, so the weight values shown here are not important.
To break down the shader, I duplicated the original, made one for each layer and changed the values of the weights for each. For example, for the diffuse pass, the weight of diffuse is 1 and epidermal, subdermal, specular, etc is 0. I only changed the weight values; all the other values were the same for all.
I used Final Gather and I made this layer (Fig.16).
Then in Photoshop, I used this blending mode to create the final skin (Fig.17).