For harder eges, I'd recommend a kneaded eraser. You can form it to the shape and pull the values out. This gives you a nice edge.
as for graphite powder, I've never used it so I can't say much about it. Seeing as its free flowing powder, I'm not sure there is much you can do to control it (or at least the application of it).
Doctors heal you, Artists immortalize you.
"Those who can, do. Those who can't, teach" - bullshit.
The usual staples for anatomy: