From my Tuchanka painting - [link]
Main progress gif here - [link]
Again I like to start with darker colours and add lighter colours as I go - looks much better than adding messy shadows!
I also add a LOT of new layers and lock them when I need to. I then normally merge the layers into just 2-3 (base and wispy strands), and use the burn (but not dodge! It sucks) tool set on 'shadows' to add in a few shadows for when e.g. a section of hair falls over another. Adds a bit of depth. None of that is very obvious up above, but then Jena has a very practical hairstyle!
For stubble, use a speckled brush to cover the area, make a big circular mask (the centre should be around the character's nose), use radial blur set to 'zoom', and mess with the settings until it looks right. Do a few layers of this, set some to multiply, lock them and paint a bit of backlight around the sides, and you're done!