I recently bought some stamps from Hobby Craft and found that one of them makes a neat portrait surround. There's nametag surrounds, but this was more fun.
After an initial test on a card I decided to go for a full session of drawing and create 24 portraits, with an attempt at creating an original character in each one.
Each portrait is around 45 x 50mm, so detail levels aren't amazing. Colours will be wonky due to my colour-blindness, although its not much of an issue since my art pens have the names of the colours on them. I just don't have the patience to figure out the colours for each character.
I'm not sure if the character in the bottom right portrait counts as "mature", but if anyone is offended please let me know and I'll mark this are mature.