I have to say that after a while the rules become second nature or automatic solutions which allows us to respond to the moment . For me their are images that take a lot of work I.E. testing and research and other times the image just happens. Either way when it comes to execution all the notes, testing and drawings are put away so I can stay in the moment. You can call it anything you want: trance, instinct Or experiance. As long as your doing it, just follow your feet and every thing is wide open to be challenged! (sorry for the soapbox)