At the start, I just jump in blindly and see where it takes me. Where my planning comes in, is after around 2000-4000 words are down and my mind starts racing through all the eventual possibilities. This leads to me having dozens of short section/chapter summaries throughout my collection of google docs and phone memos. I've got bullet lists, pictures, scribbles on loose papers, basically everything. Sometimes my computer just gets too slow on boot and I have to rush straight into the idea and get it down or it'll disappear. For example, in NWO I have three different google docs that detail various plot points that won't even appear for another 10, 15, or 20 posts. There's one in particular that just came to mind the other night, that likely won't come into play for another 50 or 60 chapters to be honest.
I really like toying with the idea of organizing myself though. I have a pretty decent sized chunk of bare wall right next to my computer screen, that I've thought of filling with sticky notes pertaining to various stories. I already have some stickies on my actual screen, just as reminders of various other things I need to do in the immediate future, so it might work out if I try that. I've wanted to try using Prezi as a way to organize my thoughts and the flow of my story, but I'm afraid that having yet another webpage to keep track of would only cause me to lose interest.