One interesting thing I found earlier was a conversation between Neil Gaiman and long time collaborator/illustrator Dave McKean, where they were talking about how they didn't gel over Mirrormask very well because they had such different approaches to writing. It gave me a couple of insights into NG's writing process, which is apparently a lot more fluid and unplanned than, for example, the one I've been using for the past few months.
That has made me have a look at the way I have produced works, and it seems to me that all the ones I've finished and been happy with (all?) have been produced in a similar way. Yet somewhere along the line, I've got it into my head that lots of planning is necessary. I'll plot out stories in detail, working out all the elements... and then I'll wonder why they no longer excite me when it comes to writing them.
I think part of it is another idea stolen from Gaiman which is that no one reads the first draft. I'm actually very picky about the first draft of novels. I don't like going back and fixing big things. Yet when I play music, I'm very much of the 'get something down and capture the moment' school. So it's time to try being more spontaneous with these things again.