It's nicely done, but you have a tangent where Sherlock's right jaw, neck, and hair all stop. If you kind of stagger those, or at least extend the hairline down a tiny bit, I think it'll look much more polished. Also, the scarf on his left (our right) looks very thin where you have it curve behind. Shortening the shading (like, literally squashing it down, not shrinking it), will help make the material look thicker if the highlighted scarf rolls around to touch his neck.
Very well done, and good lines. I hope my critique didn't offend.