I would have to strongly disagree with using the dodge/burn tool D: I may not be the best at shading, ect. but from just about any tutorial/tip video I have watched they have advised to stay away from using such a tool for shading and instead either using a solid colour with the opacity turned down (such as a dark red/blue/black/white/ect.) or using the ink dropper tool and darkening/lightening it for the shading as this gives a much better effect.
Edit: Also, really nice work! Although - make sure when using the fill tool that you get the whole area covered (as you have some thin white lines around the hat outline for example). I usually go around such lines with the pen tool to make sure they're completely filled.