I love Illustrator and am already very familiar with it so I decided to branch out a little and try this in Photoshop instead. I've also been taking classes on drawing, so this is a bit of a hybrid result. But, much of what I learned in this class guided the way I approached this. I wanted it to have a hand drawn, inky feel, but still using thick lines and minimal colors so that it wold read well as an avatar at small sizes.
My first attempt was off in a couple of key areas. The jaw was too small and it looked like I was wearing lipstick. Overall it had sort of a Peewee Herman vibe. Not the look I was going for.
After getting some helpful feedback from friends (especially my wife), I made the adjustments and am pretty happy with the result: