Bring values closer together in the hair/beard, ei, drop the lighter values in the upper and outer left of the hair to frame the face more. I like the loosness of the hair. The ripple of cloth on the right lines up with his lower lip, a little distracting and has a little too much contrast for a part of the piece that isnt very important, eye trap. Could also drop the white/lighter values on that side/cloth or whatever that is and strengthen the sihoette a little bit. Theres a lot of contrast in the left corner where his back/shoulder drops off, darken whole area to activate that space with some gravity while lowering contrast to avoid eyeballs from looking all over the place in this piece. Nice work!!!