I run free classes and seminars on breaking through writer's block or artist block for people - which is basically "sit down and do it" boiled down. The people who come really enjoy it - I had a friend run the class for me last fall with instructions and she was like "THAT WAS THE BEST THING EVERRRR" and said the people who showed up really enjoyed it!
I'm glad I've gotten to the point where I can just hand the directions off to someone else and they can facilitate it.
In the past I've also taught seminars on public speaking voice /voice acting, in the vein of public theatre where you don't get mics and "do overs".
If I could do another, I'd like to be able to facilitate art with a more messy medium - like paints, tye-dye, or something else. It's super messy but I think it'd be a lot of fun for the people doing it. Sometimes doing the weird mindless art is the perfect thing to bond with someone over, or to get through some kind of block.
If I wasn't doing seminars, likely I'd want to learn about how to facilitate art therapy.