/ic/ - Artwork/Critique

Couple of distinct questions:

What is the best way to learn to draw faces which actually look like specific people, rather than just generic ones? I think I can do OK faces, but they just kind of come out how they do rather than really looking like the model I am referencing or the specific person I am trying to draw.
How do I get good at drawing people's backs? Especially the shoulder blades. I swear, they are the hardest part of the human body to get right.
Where can I find good reference images of feet?

I use firealpaca on a pretty low-end laptop and it generally works well.