Regarding sleep, I also learned to "take it easy", so to speak. Instead of thinking "I have to get up soon, fall asleep already!!", I simply think "oh well, I might not sleep but at least I can rest my body a bit and think about stuff". I find that inventing things, be their stories, or imaginary programs, helps with drifting over from that into sleep.

As for creativity, I don't know if it's good for overall output volume, but I love to have a lot of things in the oven, on the backburner, and in the pantry, and switching occasionally. Sometimes I find that something I was burned out on excites me again, and other times I realize that something I was totally obsessed with for a short while after coming up with it isn't really that good, which is just as important.