I find bliss when I improvise alone with zero agenda. I just play free and jump into the unknown. It's like meditation.
"I always play into the unknown. I don't practice things that are known to me unless I'm getting ready to do live work. Most of the time, it's abstract, like picking up a pencil and paper and drawing what's in front of me. It's improvised, always." - Eric Clapton
I have a theory of what creativity actually is. I think it's connecting things that were never connected before. None of us invented music notes, but we can connect them together in ways that no one else has ever done before. So when I improvise alone, I disconnect the rational judgmental part of my brain and I let my fingers and mind explore and make neural connections where there never where any.
And then later, I can take those pure ideas, put on my rational hat and arrange them into something. But if you don't disconnect the judgment part of your brain in the first phase, it's super hard to be creative. For me, anyway.