In the end, there is no ideal condition for creativity. What works for one person is useless for another. The only criterion is this: Make it easy on yourself. Find a working environment where the prospect of wrestling with your muse doesn't scare you, doesn't shut you down. It should make you want to be there, and once you find it, stick with it. To get the creative habit, you need a working environment that's habit-forming. All preferred working states, no matter how eccentric, have one thing in common: When you enter into them, they compel you to get started.