From Publishers Weekly:
Outlining a novel in the traditional sense is impossible for someone whose car looks like a crime scene and whose kitchen cabinets are home to unnatural hook-ups between pots, pans, and Tupperware.
Like guests arriving before the start of a party, my characters inevitably show up before the plot. Which makes sense because I’m wildly interested in people—who they are, how they got that way, what makes them cringe—and congenitally unable to plan. Unlike some of my writer friends, who approach their opening lines only after constructing complete blueprints of everything between preface and epilogue, I’ve found that there’s more than one way to write a page-turner. A good thing, because the idea of creating a scene-by-scene synopsis makes my teeth hurt. So below is my five-part equation.
In lieu of a standard outline, you need a one-line description of what’s going to happen. That’s it. An elevator pitch. Something that you can refer to when things seem to be getting out of hand. Put it on a sticky note on the top of your computer screen. (The North Star for the muddled.) In the case of my medical thriller, Best Intentions, the pitch was: “A hospital social worker committed to helping others witnesses something terrible and ends up on trial for murder.”
The second part of the formula is having a deep understanding of the characters inhabiting your novel (whom they voted for, what’s inside their purses, what they do when they think they’re alone). That way, when they all board the plane you’re ushering them onto (and the general flight plan incrementally reveals itself), the characters will respond to each other and what you throw at them in ways that not only make sense but also help the narrative along.
Link to the rest at Publishers Weekly