I'm doing some ATC trades with people, and here's three I've gotten done. I have two more to go. These are on bristol cards that are 2.5x3.5 inches so they're fairly small. I use copic marker to do them (and white ink). They're a fun little challenge to see what I can feasibly fit on such a small size and still make look good.
Alencia, Fran Rowan's character for her comic in progress. Her blog: http://clockworkqueen.blogspot.com/