There are two camps of thought: the people who listen to the muse and write by the seat of their pants and the people who write an entire book-length outline prior to starting to write.
I prefer to combine the two, without writing an entire book-length outline. Let me explain my thoughts on this debate.
Pantsers argue they are free to listen to the story and the characters. It is a muse-centric approach, with the characters exploring the milieu and wandering about discovering the story. All fine and well. It is interesting how a story can take on a life and allow a writer to document scenes and fill in the story.
Plotters say there is no way a story can take shape without a road map: it requires a structure to allow the characters to face their inner and external conflicts. The characters are forced to face their fears. Plotters like to know where the story is headed.
Here is my take: Pantsers need to outline and Plotters need to be open to just writing.
In my experience, without an outline I have twice been abandoned by my characters in the second act. They exhibit attention deficit disorder and climb out of the book. The characters say “well, that’s all I got,” and the story sort of fizzles out. I’m rewriting “Fish Tacos: Or How I Went To Mexico to Save My Soul” because the main character started bitching about his past and failed to get off his butt. Sure, I’m the writer, it is my story, but I let the character dictate where he would go and when he would get there. Believe me, if left to his designs, the main character would still be sitting in the desert waiting to move.
So now I plot everything: short stories; novels; non-fiction; and, screenplays. I give the viewpoint characters a purpose and a timeline to meet. I challenge them to face their demons. I gift them happy successes. By the time the story ends, they see their doubts, obstacles, challenges, and growth.
In some ways this is the perfect way to write by the seat of your pants: the story structure lets them wander about, as long as they meet their deadlines. So I guess I’m a Pantser Plotter . It seems to be working.