I've learned a lot of things drawing faces. Some expected things about line and shading. Some unexpected things too. For example, when I was looking in popular magazines for interesting faces to draw, I found the men's faces more interesting than I found the women's faces. As I drew women, I found I was drawing similar things over and over. With the men, I found different shapes.
I found interesting hats.
Some ended up looking like villain characters.
Some were easy to make recognizable - they were so unique.
Some were skinny and some were chubby.
Some had great big cheesy grins.
The conclusion I arrived at was that men get their pictures in popular magazines by virtue of their accomplishments. Women get their pictures in popular magazines because they meet the popular standards for beauty. Which means they all look similar, particularly when drawn in black and white, without hair, eye, and lipstick colour to differentiate them. I found this made me sad.