A few ATC round robins, where the starting card was a playing card (which makes the finished product an APC - Altered Playing Card) - these had no particular theme, just whatever we wanted to add. I was the second player in both cases, so can show the finished card (above),
what it looked like when I'd added to it
and how it started out.
Again, the finished product,
after my additions
and how it came to me in the first place.