I plan my novels. Extensively. This generally consists of me writing a complete workup in advance: brief synopsis, themes, style, character profiles, and a detailed plot outline. The one for The Hundred Thousand Kingdoms was 19 pages long; this is a short one for me. I more or less stick to this outline. (More “less” than “more” — the outline contains one- or two-sentence descriptions of what usually become whole chapters or multiple chapters in the story.)
But although the core story of a novel is usually quite clear to me, I don’t always get a solid bead on the direction I want to take until I’ve written a few chapters. Sometimes this changes things, even after I’ve written an outline. I’m in that position right now with Book 3; I’ve written several different test chapters and realized that the outline I’d written, in which a particular character is the PoV and protagonist, isn’t going to work. I’ve decided to write another character as the PoV person. So now I have to go back and rewrite the outline from scratch.
I don’t consider this time a loss, though — nor do I consider the outline too much work. I used to write by the seat of my pants, and found that I wrote too many chapters that went down blind alleyways; my plots floundered too much. It took longer to write the book. So for the past 5 or 6 years, I’ve been a staunch advocate of outlining.
(Well, I am a Virgo.)