This is an interesting site: How To Write A Novel Using The Snowflake Method. I like the idea of starting with a one-line description of the story and working out to a full outline, though I suspect it’s too constrictive for my taste.
However, by doing the one line to multi-paragraph outline, I have realised that the character I thought was the main character in The Thing is probably not, and that The Thing is probably the villain rather than the MacGuffin. So some rewriting is probably required when I get around to revisiting that story.
That said, I’d half-realised the former already because I’d spent a lot more time writing his story than the story of the character I thought was the main one. Also, I’d been thinking that I should make that character’s family less sympathetic, so this gives me an excuse to do that.
Perhaps I’ll give this a more serious try for the next novel I write.