Personally, I've found one of the more stimulating ways of playing in recent times has been to kind of move outside the free improvised area and work with people who are probably improvisers but they have a particular way of working.
“I desire to put off my trial as long as I can till I can get my evidence ready.”
“Nobody ever worked as hard as my father. My father averaged maybe four hours of sleep at night, and when you're a kid, you don't realize that.”