These are some things I doodled while playing in Courtney's Numenhalla game this morning. And a couple I did while running D&D&LB later that same night.
Most of the time when I doodle, I've got some specific piece of anatomy I'm curious to experiment with, and I do a ton of sketches where that piece of anatomy is the focus. Here I did a few different doodles of people opening their lips and exposing their gums, for example.