100 Faces Pt 1

In order to become a better artist I'm attempting to focus on one specific weakness at a time, at least for a short period, to gain a better handle on it. One of my biggest weaknesses, at least in my opinion, are faces. So I've decided to give myself the challenge of 100 faces in a month. I plan to vary a lil by age, size, race, and gender. Any suggestions and critiques are welcome.