There are typically two ways a Wrimo can get through NaNoWriMo: plotting and pantsing. The first involves careful planification of your novel before Nov. 1 hits and the second involves, well, winging the entire story. Each category has its own extremes, but also a multitude of in-betweens.
I have tried both techniques, and discovered I am a plotter. Last year I had a complete outline with every scene for my first novel and I breezed through it. Every now and then I added a scene, removed one or extended another, but it never veered of course.
Ten days after the start, I was done. And I was forced to take the pantsers' way.
It turned out okay, although I am now rewriting that novel. It's easier to do that than major edits. What I realised, though, is that every day during classes (shhh!) I would plan out the next 6-7k of my novel, to be written when the evening came. I could not come home with no idea of what was going to happen. I needed that plan. So even when forced to spontaneously write a story, I ended up planning it.
What works for me does not always work for others, however. How about you, Wrimos? Are you Plot, or are you Pants?