Skin high and lowlights.....

To create a more realistic skin tone, I added high and low areas to simulate the shine caused by oily areas of the face like the nose and cheeks.

Here's how the Specular Map looked in Photoshop....



And the effect on the skin once it had been loaded into the material channel....



I played around with the levels until I was happy with the results. Having the Specular level too high caused way too much glare on the face so I turned it down to 35 which seemed about right.

The materials channels: