I sometimes refer to style books when I run into a problem in my writing, but I do not use them for the entire piece. Since my writing comes basically from the heart, I find it easier to just write as it comes, then let it sit for a few days and review it and edit later.
When I use style books, my writing seems more stilted and forced. Often my best stories are those that just write themselves from a single opening line. Its like a pilot that flies "by the seat of his pants." It can be dangerous, but it is less mechanical and a lot more fun.
Now if I were writing nonfiction, I would probably be more organized and use a style book for that type of writing, but most of my writing is either journaling, essay, poetry or fiction.