I never ever wanted to do this for a commission unless it was my own figure, but it somehow fell in my lap with a bulk order for one of my clients that decide to toss him in as a extra, never again unless it's for my own collection, OOAK.
He wanted a grimace look to him so I did the best I could to mimic the effect with paint, the sculpt really has sort of a neutral gaze so it was a tall order without any sculpt modification.
Nice work on Maul... it's a difficult one since there is just enough wrong with it that paint just doesn't quite give him the intensity needed.
Did you see the eyelid and brow resculpt posted in the SW custom section... really made a difference in how he looked. I plan to redo mine when I have the time.