I kind of do the same thing, only less rigorously. When I start out, I:
- Write the first section of the first chapter.
- Write the last section of the last chapter (or epilogue, where applicable).
- Create a very coarse plot point list containing key events that I expect to write about.
- Delete the bullets as I write, adding chapter breaks wherever it seems natural to stop.
I don't attempt to think about chapters while planning, and I don't typically include side plots as part of that list—only the main plot. Secondary story arcs tend to just spring up randomly as I'm writing, and I weave them into the story wherever I can make them fit. I doubt more than half of the plot points ever actually make the list.
Often, my coarse plot point list doesn't even go all the way from the beginning to the end. It might initially cover only the first and last couple of chapters. What matters most is knowing where you are and where you're trying to eventually be. As I write towards the destination, I'll randomly think of an idea for a direction that the story could go along the way. When that happens, I add it to my bullet point list and keep writing. Eventually, I reach that plot point, and I write about it, then start writing my way towards the next point.
Of course, I don't always go directly from one plot point to the next. Often the path from point A to point B gets long and circuitous—I think the longest unplotted run in
Beyond the Veil was approaching twenty pages—but I know that eventually I must reach that next plot point (somehow), so I'm always writing with that next goal in mind.
With that said, sometimes a better idea comes along while I'm getting there, and I delete an existing plot point and replace it with something very different. This sometimes requires tweaking other future plot points, but eventually the basic story gets back on track. Thus, the plot point list is a living document up until the moment it ceases to exist (when I finish writing the last chapter).