I led an art class about how to paint and otherwise render a realistic yet artistic “winter Steelhead”.  It was fun for me, and an opportunity for the students to use media they might not have.
It was touted as a “watercolor” class for beginners, but in the end we talked about and used gouache and watercolor pencils.  This was from 9-4 on a Saturday, so a nice long session.  I have certainly run out of time in other classes, and despite me shoving us along throughout the day, we stuck to my timeline and finished right at 4.  Amazing.  The students turned out some super awesome work, especially as some of them never painted fish nor used any of those highly finicky media before.