Well, I'm late to the party, but I figured I'd contribute anyway
Typically, I create an outline for a story, start to finish, before I start writing, so I at least have a basic road map, and I know where my start and end points are. I don't force myself to stick to the outline once I've started, but I've found that an outline helps me keep a basic tally of all my running plot lines, gives me a general time line for when I want to introduce new story bits, and reminds me where I want to go. If I change my mind and decide to go in a new direction while I'm writing, I always take a few nights off from writing to rewrite my outline. I *always* need to have a clear end point, or I feel like I'm flailing instead of writing.
Once I have an outline, I'll write and post chapter by chapter. I get each chapter beta-ed individually. If the audience isn't receiving something like I thought it would, I might amend future chapters and story directions, but what's posted, I consider final. I do, however, always appreciate and encourage constructive feedback even on parts I've posted and 'finished'. I say my mea culpas and use that constructive feedback as advice for the future.
I used to finish stories before I posted them, way back when I used to write shorter pieces, and I didn't mind waiting a month for feedback. But in recent years, I've started tackling projects that take me a year or more to write, not because of lack of time, but because they are so. SO. LONG.
My current WIP is about 220k words thus far. I've been working on it since May, and I've only written 14/30 planned chapters. The last long story I wrote was over 460k words, and it took me a little less than a year to complete.
I'm a procrastinator. If I have a project, I'm likely to stop working on it at some point. I rarely finish anything. *Except* my writing. I always finish that. Why? I write for myself, yes, but I also write to tell stories. To entertain people. I've come to rely on feedback as motivation to continue. I know that if there are people out there waiting to find out what happens, I'm more inclined to push through rough spots and bad evenings where I just don't feel like writing anything at all.
So, really, I use boards like these, or my livejournal, or ffnet, or what have you, as, not only a tool to help myself improve my writing, but as a motivational impetus to keep going and finish my monstrous projects.
