I'd like to say that getting into this state (of subconsious) can also be trained. I found that light meditation (e.g. "slow flow yoga") helps to access this in various moments when you need it, especially sitting down and doing your work! There is a nice book about a writers struggles to write called the War Of Art by Steven Pressfied. He describes what you wrote as "letting the muse in", a force that enters us when we do a creative work, something greater than us that we should respect and nourish. A nice post, thank you!