PBR Skin Shader for your projects. Uses diffuse, subsurface scattering and displacement maps. If you are using normal maps for your models - replace displacement-related "Bump" node to "Normal Map" node. PBR Shader consists of two main parts: SSS/Diffuse mix group and Specular overlay group. Both groups are controlled by "roughness" values, which define Fresnel nodes power and roughness of diffuse/glossy shaders. For mirror/wet/oily effect try to decrease "roughness" values, for dry skin effect (less specular in total mix) - increase roughness values. For fine tuning of shaders your can change values within Fresnel nodes or add an external specular/roughness map for control values of roughness for the fresnel/shaders, but by default most of work performed in this shader solely by Fresnel node in PBR-style. Different materials on Genesis dummy show some key issues of skin shader.

Fresnel node used for skin shader: https://www.blendswap.com/blends/view/80110

Video tutorial for Fresnel tuning: https://www.youtube.com/watch?v=6pJrlEzbNek&feature=youtu.be

Diffuse/SSS/Displacement maps and Genesis3 dummy model by Daz3D

Mouth/Teeth/Eyes/Cornea shaders inspired by Manuel Bastioni project: http://www.manuelbastioni.com/