I can’t pants it. I can’t write organically. I’ve tried.
I’ve gotta consciously know where I’m going. I’ve learned that if I don’t know how the story ends, I can’t finish it. Many a novel and short story of mine has floundered because of this.
I did finish a novel once, trying (somewhat) to write it organically. The ending turned out pretty pathetic. I think at that point, I was simply trying to finish a novel, pushing through.
My next novel, I wrote a four-page, scene-by-scene outline (sixty-four scenes!). I knew how it began, I knew how it ended, and I knew what had to happen in the middle. Result: finished novel I was happier with.
Since then, when I conceive a novel, I begin with a concept or spark. (Regency Romance with Magic! -or- “I am currently unsupervised. I know. It scares me too, but the possibilities are endless!”) I work out my main characters (always called Our Heroine, at first), then I work out the bones of the plot, including how it ends. Especially how it ends. I don’t have to be specific on the stuff that happens in the middle, but I must have that ending.
If I don’t have that architecture in place, I’ll end up floundering somewhere in the middle, then peter out, wondering, “Now what?”
(And now, let us have a few moments of silence for all the novels I started without knowing how they ended, and are now resting forgotten in the bottom of the trunk. Sorry, Marinda.)