/ic/ - Artwork/Critique

Here's how I've been spending the morning. That statue thread is absolutely awesome. Feedback so far?

Can anyone point me to good rendering techniques? It takes me a long time of tweaking to get to this sort of result, which I think doesn't look terrible, but is also kind of muddy and could be achieved more quickly. Is it just a question of practice and building confidence with my values and strokes, or is there something wrong with my rendering technique on a fundamental level?

Also, how do I into faces? Lots of failed attempts of getting the likeness in this drawing already.