I suspect that Parker... my favorite writer on BDSMLibrary, just a hair ahead of Woodsman'sGame, Kallie Thomas, and Faibhar... doesn't outline and just writes plots off the top of his head.

But that's because he's a brilliant writer-- not everyone can do the complex plot thing, planning or not.

For a new writer starting out, I do recommend habits of discipline. Outlining plots will probably help. But don't get locked in to something if you see a better path.