Some writers swear by outlines. Some writers swear at them.
I've done both.
For my most recent novel, House of Whispers, I wrote a detailed outline. The publisher requested a synopsis, and the only way I could see to come up with one for a book I hadn't written yet was to figure out the whole story, scene by scene, and then condense it into a couple of pages. Developing the outline was hard work. It made my brain hurt. But once it was finished, writing the book went quickly and smoothly, and the creative pleasure didn't diminish at all. It was fun to add flesh to the bare bones of the story and bring it life. I was more than willing to change the outline if the story turned out to require that, but it didn't prove necessary.
The follow-up book, House of Desire, resisted every effort I made to outline it. So I plunged in, discovering the story as I wrote it. I can see why this approach might appeal to an author. The theory is that if you don't plan it in advance, the story will retain its freshness and its ability to surprise. True enough, but for me, not knowing what was going to happen next has proved to be a burden. I've just finished the first draft, which took much longer than I anticipated. The plot kept veering off in unexpected directions, which meant that much of what I set up at the beginning never played out, while the eventual resolution was never set up. I have a big rewrite ahead of me.
I had the best of both worlds when wrote my first mystery, A Relative Stranger. I came up with a three-stage technique that I call the 1-2-3 outline. My plan was to plot out the novel in some detail, but by the time I'd figured out a third of the story, I'd grown impatient to begin writing. I was eager to see the characters in action, to see my vision take shape on the page. I put aside my outline and wrote several chapters.
Soon I reached uncharted territory. Writing grew difficult. I couldn't move forward because I didn't know what happened next. So I outlined another chunk. Satisfied that I'd reestablished my sense of direction, I wrote those chapters. Finally, I plotted the ending and completed the first draft. Later I read about the three-act story structure that screenwriters and some novelists use, and realized I'd stumbled on it instinctively.
This back-and-forth process, alternating stages of planning with stages of actually writing, worked well. It gave me control of the story while keeping it fresh, vital and open to surprise. It let me take advantage of serendipity--those fortuitous elements that the Muse slips into the story when you're not paying full attention, ideas that would never occur to you while outlining.
For example, early in A Relative Stranger, my detective Jess Randolph enters the murder victim's apartment. Her artist's eye is drawn to a painting on the wall. When I wrote the scene, the painting was just set decoration, a prop to give a tidbit of insight into both Jess and the victim. Imagine my surprise when, several chapters later, the painting was stolen in what turned out be a key twist of the plot. It was too minor a detail at first to surface in my mind during the planning phase. Had I outlined the book straight through, I wouldn't have known the painting was there, and I would have lost a valuable opportunity.The lesson here, if there is one, is that what works for one author, or even for one book, might not work at all for another. To outline or not? It's question that we all must answer on our own.