Time's up! This portrait of Svante isn't going to get any better if I futz with it more. Dude has interesting lips. Also interesting: what happens behind his glasses.
I've been using highlighting more as a technique. Just going over the image with a white (digital) pencil. It works. Didn't bother to render the intricate texture of his shirt, though.
I really need to study the musculature of the face. I'm becoming more aware of it, and of how not seeing it properly makes the expressions fall flat.