The head is beautifully rendered! Tons of personality there. As far as poses go, you can and should use a pose inform your characters personality. It doesn't have to be anything crazy dynamic and complicated. Would they stand with clenched hands or loose? Would they bend their knees? Put weight on one leg? Most of the trouble I run into with poses comes from not thinking about the motivation for making said pose.
I'd suggest getting in front of a mirror and acting out your character. A good pose can go a long way in realizing a personality, even if it's just a character sheet!