I wrote both my NaNoWriMo books as a pantser. What is a pantser? A pantser is someone who writes by the seat of their pants, with no pre-planning. By contrast, plotters are those who outline and plot out their story before writing. There is a fairly lively debate on the internet about which style works best. See some pro-pantser arguments here and a very strong pro-plotter case here. I’m pretty convinced Stephen King is also a pantser based on his description of his process in his memoir.
Here’s the thing, though. I think you need to have a lot of experience with story structure to be able to successfully pants. When you have enough expertise, and you have truly internalized the rules, then it just shows up in your writing. See for example Jami Gold’s description here and here of how her pantsed novel ended up having pretty much the exact pacing of a standard type of story structure.
But, if you don’t have enough experience, I don’t think you’ll be quite as successful. I think then plotting does help you create a story with a decent pace and enough plot that it is interesting. I assumed because I read a lot (and write a lot of technical work) that I would be able to produce a halfway decent story. I thought consuming thrillers and mysteries would be sufficient to internalize the needed structure and pacing requirements. It isn’t At least for not for me.
When I went to map out my story’s structure (using Jami Gold’s basic beat sheet), I found that I’m missing a lot of key “beats” or plot points. The pacing is terrible. Part of that is a consequence of the format of NaNoWriMo- having to produce 50,000 words in a month does tend to encourage padding when the muse has left you. Part of it is because I’m missing a lot of obvious opportunities to increase the tension and drama. So, I’ve started to revise my novel by plotting it. I’ve already deconstructed everything into scenes, so next, I can plot it, and then I can fit my scenes back where they need to go.
Just for fun, I pulled a thriller/mystery off my shelf. The author has won numerous writing awards, so I figured this would be a reasonable check of the basic beat sheet concept. I sat down and read the book with pen and paper. Every major plot point I wrote down along with the page number, and yeah, it matched the classic structure exactly. Reading a book to understand the structure is a fascinating way to read. Despite taking a ridiculous number of literature classes in college, I never was exposed to this way of reading. I highly recommend re-reading an old favorite and mapping it onto a beat sheet so you can see how it all fits together.
For now, I firmly a plotter. Hopefully, as my skill as a fiction writer improves, I will become able to pants. It is a lot of fun just to sit down and bang out a novel with no pre-planning. But it is less fun when you realize how much time it will take to revise the novel.