Try these:
* Sleep one hour less a night.
* Don't drink alcohol.
* Prepare all food for the week in advance.
* Cut down your time from awake to shaved, showered, dressed to 15 minutes.
* Work less at your day job.
* I don't drink alcohol at all.
* Nice idea about food, which I mostly follow. Not all food can stay palatable for a week, though.
* Faster startup is a nice idea, too.
* Working less on my day job would be nice, but probably my employer won't be happy. I'm not overworking.
My best moments of clarity are on my hour long morning drive after a good night's sleep, not when I'm actually doing the work.
The only 'controversial' one is sleep - which can vary by experience. If you're sleeping 9 hours, cutting 1 hour back to 8 shouldn't be catastrophic. If you're already only sleeping 6, then it's a different story.