I refer to this blog post frequently when teaching or explaining diffuse wrap as a valuable tool for particle lighting - it’s a bit verbose on shader math (unless you’re writing a shader…) but it’s worth looking over and understanding how such a simple and cheap trick can go so far to create the illusion of sub-surface light scatter, especially when you drive it with a “density” texture.
http://blog.stevemcauley.com/2011/12/03/energy-conserving-wrapped-diffuse/