Fountain of Knowledge

When you're writing, where do you start? Where do you finish? I know, open ended question, I'll be more specific.

I've written first drafts of two different novels (yeah, I didn't say finished ). The first one I just sat down and wrote. Well, it took me a year or two to do so, because I kept fumbling with tieing it all together, but once I had the idea, I did just that. The second one I did a little more planning with, but not a lot. I was listening to a CD that inspired me. I used each track to plot out a specific character shift in the story, put it all in a logical order, and then wrote from that.

So I'm wondering how other people do it, because I'm having trouble recreating this phenomenon. I need to write more stuff and it's not working. Do you write outlines or just let the story flow? If you do outlines, how detailed are they? Scene by scene, or something else? Or do you create a character or two, stick them in a setting, and then just ask them what they want to do next?