Into my head! I have a fictional story going in my mind all the time. I like to lay down and go to this place, add details to the story, move it all along with twists and turns. Sometimes at night I get so involved and excited about where the story is going I can't fall asleep.
I started this method years ago ( early 70's) during a severe depression. I could not sleep so as I lay there I started the kind of story I enjoyed reading. Each night I added more details, more plot and eventually I was looking forward to going to bed to see where the story would go.
It ended up being my first book, A Distant Calling. I've used this method every since then when I really need to escape this life for a little bit.