My first selfie! Can't say I enjoyed doing this, painting values - ok, but trying to draw myself from life was one of the most frustrating moments of everything art related I ever did D:
Mass light/Mass Shadow - my light source was a window, and as it was gettting darker my painting assumed a more low key aspect, making the mass lights and mass shadows similiar in value than if I was using a spotlight. The mass light is takes most of the left side of the face.
Half tone - As I didn't use a direct spotlight the haltones were dominant. I think halftones are the most important to give what you're paiting a sense of 3D
Highlights - subtle highlights only, mainly cheekbones, tip of the nose and cupid's bow (I have no idea if that's the word for it)
Fill Light - on the right side of the face, concentrated on the edge of the cheek, brow bone and the hollow(?) of the eye
Core Shadow - edges of the eyes, nostril
Cast Shadow- I think I could've gone bolder on cast shadows, more spcifically aroud the nose, to really show there's an edge there.