There is really nothing quite like reading a good book. You find a comfy chair and you wriggle into a space-time nook away from stress and the tentacular crap that so invades our walk-a-day
Writing or illustrating a book, means an even deeper nestle. You burrow down and gather your wits and fluff. You grow moth antennae to gather idea molecules. You are searching, searching...for what? Your job is now to dream. It is now possible to zoom around the universe. Find the goodies that float like dust in a ray of light. As hunter/gatherers we tuck in the bits of treasure, or junk (which was once or will again become treasure).
There is no way that I know to get around being a space cadet when hunkered down in the brainstorming state. It can be treacherous. I have sometimes fallen off the planet. It's true, ask my wife. One time when I was in this condition, I was wandering around Egypt. Walking on some rickety railroad tracks. I was daydreaming, searching for reference and bits of ideas. I was getting in touch with my inner pharaoh, when a little hieroglyphic of a voice said, "Probably shouldn't walk on train tracks". So I stepped off, and out of nowhere this locomotive blasted past me like a mummy with a caffeine fix. I never heard it coming.
I love this process. You make new friends and keep the old, with the help of guardian angels.