Sometimes when I begin a novel I know where it begins. And sometimes I know where it should begin, after I've written what turns out not to be the beginning after all. As for what follows, I have several characters, an idea that entangles them, and an outline that always turns out be only partly compatible with what the characters want or need to do. That difficult middle bit, which is actually most of the novel's narrative, is written sentence by sentence, paragraph by paragraph, chapter by chapter, discovering the beats of the narrative as it unfolds.
It's not a way of writing a novel I'd recommend. It's an uncertain start-and stop-and-start-over business. It's a process of discovery that can lead to all kinds of inconvenient dead patches and false trails caused by trying to force the characters down a path until you realise they wouldn't have taken at all, if only you had listened to them. So then you have to backtrack until you discover where the paths diverged, and you start over from there. How much nicer it would be to know exactly where you are and where you have to go next at every point, to be able to fill your required word count every day and know that you are that much closer to the end! Instead, I write sort of first drafts that mix actual first-draft material with chunks of rewritten and repurposed stuff. But it's the only way I know how to do it, and while the way points of the outline quite often evaporate or turn out to be in the wrong place, at least I always know where the end is, and what it looks like.
I'm getting close the end point of
Into Everywhere, the sort-of-sequel (continued by different characters) to
Something Coming Through. I can see the exit, and a strategy to get there is beginning to resolve. I've been playing a lot of Philip Glass while writing this one. Particularly the soundtrack of
Powaqqatsi. Maybe the significance of that will become clear when I reach the exit.