Mary Robinette Kowal recently described an interesting storytelling phenomenon that happened to her.

She read one of her unfinished stories to a group of people she knew. She got to the place where the story ended (without ending) and the audience wanted to know ...

But what happens next?!?!"

I glanced at all the sharp instruments they had in their hands, decided that my life was in danger, and told them the rest of the story. My word-smithery went out the window pretty fast leaving me with voice to convey mood and then... the rest was all about the plot. What happened next.

I knew basically what I wanted to have happen, but I hadn't worked out any of the details yet. Having a live audience listening to me as I found my way through the rest of the plot points showed me exactly which things were interesting and which weren't. (The car chase is right out.) If they had a question, I could stop for exposition, (See, the Faerie Queen knew there was a traitor, she just didn't know who) while making a mental note that I needed to plant that piece of information earlier when actually writing it.

When I got out of there, I sat down with the keyboard and the words fairly flew out of me. I still have a couple of thousand words to go, but I know exactly what happens next.

Interesting idea for writers -- try telling the unfinished part of your story and see how the telling affects your writing.