Recently I posted a comment on FB that I had reached 57,000+ words in my work-in-progress and now, at last, knew how it was going to end. This sounds absurd to anyone but another writer, and has become more and more likely in my work.
When I began writing the Mellingham series in the 1990s, I knew who the killer was, the motive, and how the final scenes would play out. The problem was getting there, how did I begin with a killer and a sleuth and keep them occupied through 70,000 words. My first step was to decide on ten chapters with ten scenes each. This idea had flaws, which I discovered in chapter one. Some scenes were long and others were short and some were repetitive because I was determined to get those ten scenes into that chapter. By the end of the book I might not even have ten chapters; instead I had eleven or nine. Sticking to a rigid plan was harder than I expected. I dropped the ten-chapters idea.
I once read a short story that went on for almost fifty pages without a single scene break. (Some of you may know this story, and if so, leave me a note in the comments.) I read with one part of my brain watching how she did this, how she managed to keep the pace and scenes threaded together without exhausting the reader, who usually expects a moment of rest for a deep breath and assimilation. I'm not likely to try this approach in crime fiction.
My current approach is to give each day a chapter regardless of how many scenes that involves. In a busy day for my MC, that could mean up to nine scenes. My tendency is to mark a scene change when the emotional tone of the action changes, and this can be even in the middle of a conversation. My Beta readers often comment on this in negative terms so I've had to revise my thinking, but I do so somewhat reluctantly. I like my placement of scene changes because I think they signal something to the reader.
After I have a completed first draft I expect I'll have to go back to the beginning and reorganize the scenes into more logical chapters, but right now this is the structure that gets me through the writing and keeps me moving forward. I didn't say it was logical. It's useful. And as a writer I am always practical. What devices do you use to push your way through the first draft?