I do a lot of planning for every novel. I have the whole thing roughly laid out before I start writing and I decide what I want to accomplish each day before I begin. And yet, I never sit down to think about my writing. All my best ideas come when I am brushing my teeth or weeding the garden. Then, when I do sit down to write, the unplanned, unanticipated bits are so often the best products of any writing session. Furthermore, if I need to solve a particular writing problem, I can’t sit down and stare at the screen or the page. I have to take a hike instead, or do some housework, or go to sleep.
All of which makes me conclude that my un-, sub-, and super-*conscious brain is a better writer than my conscious one. And I speculate that all the planning and the structure are craft equivalents of brushing my teeth: they give my conscious brain something to do while the rest of my brain gets the real job done.
*Damn, now where did I get that phrasing from? “Un-, sub-, and supernatural forces” I think that is how the original went … something by Stoppard, I believe… Rosencrantz?