Way back in the day I started off as a total pantster, just sat down and wrote whatever came to mind. But it wasn't long before I started making notes about my characters, tried to figure out who they were. Then came chapter notes, little blurbs about what would would happen, but still, mostly pantsting. Then, one day, I finally bit the bullet and outlined an entire novel, extensively interviewed my main characters and delved into theme and plot. This worked out rather well, and I thought, damn, that's slick! I was so happy thinking I'd found the perfect way to write a book. Until I tried it again with the next one.
This led to me starting completely over with a brand new toy and a brand new way of figuring out how it works, which, for the record, I haven't. But one of these days I am going to find the method that works every time, the perfect combo between outlining and pantsting. My holy grail. I swear sometimes I catch glimpses of it.