Peter Diefenthaler presents a technique for fast SSS simulation.
In this Blender video tutorial, you'll learn the process of achieving a fake and fast rendering subsurface scattering effect. You'll first learn how to create a reusable node material that resembles translucency/backscatter, then go on to assemble a reusable node group in the compositor that simulates diffusion. The method isn't perfect, but it renders much faster than other SSS methods. The example in the tutorial is extreme, but for rendering things like skin, this technique may be all you need.