Using an Outline in Plotting a Novel

The more I write, the more I've come to realize that some kind of outline is a necessary tool as I work on a novel. I didn't use an outline for my first three novels at all, can't recall really using one for my fourth, and had only the vaguest of outlines in my mind for my fifth novel (The Suicide Collectors). It's only been a relatively recent development (Wormwood, Nevada) for me to actually write out an outline in my little sketch book and try to stick to it, more or less.

I know some writers swear by a detailed outline (like John Irving), but mine are pretty bare bones affairs, with one chapter as a number and one sentence describing what happens in that chapter. For example:

Part One

1. Billy finds out he can fly
2. Billy robs a liquor store
3. Billy gets drunk and flies into a building
4. Billy goes to super hero rehab

It's not that my novels have become so complicated I can't keep the plot points straight-it's just easier for me to sit down and write everyday if I have a vague idea of where I'm going. Yet, I do prefer to keep the outline pretty vague, so I can still have a chance at surprising myself when I'm writing a scene. Outlines can be changed and mended a half-dozen times or more as I move through the process, especially during the editing stage. I tend to write linear stories, with a minimum of twists, and that also makes plotting an outline easier.