How do you capture ideas?

I think any creative type knows the drill: you're walking out to your car and inspiration hits. Or you're just about to hop in the shower when that scene you've been agonizing over finally crystallizes. Or worse yet, you're deep in revisions (dreaded, dreaded revisions) and a shiny new idea smacks you upside the head.

What do you do? Follow the rabbit down the hole and potentially write the next Hunger Games? Push the thought aside and focus on the task at hand and maybe lose your brilliant idea? Sit on the idea until it becomes something worth pursuing as it foments in the back of your mind? Or scribble it down and shove it in a file somewhere to come back to later?

Inspiration is a funny thing for me. When I first started writing, I would chase down every idea by writing it out until I couldn't think anything up anymore. What this translated to as a young writer (like, 10) was that I never finished anything. ANYTHING. In fact, the very first time I finished an entire manuscript, I was shocked that I'd actually finished something. Chasing down every idea left me scatterbrained and half finished, and that wasn't going to drive anything forward. I also never had time to practice craft because I was spending all of my time in that first feverish state of writing when you're willing to stay up until four in the morning just to capture a whisper in your mind.

So then for a while, I made myself focus. If an interesting scene or premise popped into my head while I was working on something, I set it aside and didn't follow up on it. My thought was if it was interesting enough to pursue in the future, it would stick around long enough to be told. I had the same approach to songwriting (back when I wrote songs); if a melody was good enough to be remembered, I would remember it without recording it. So of course, this meant I lost tons of ideas. Sometimes I'd have the perfect dialog exchange with myself in the car on the way home, and by the time I got around to writing it I couldn't remember half of what I'd said. So what I ended up with on the page was wooden and boring, a shadow of it's car self.

Which brings me to my current approach to capturing ideas. It's a flawed system, I'll admit that up front, and the hyper-efficient organization freak inside me wants a real system, but so far it's been a good blending of my two prior approaches. When inspirations strikes, whether I'm at the grocery store or sitting in front of my computer at work, I sit on it. I spin out the web of the story and look for ways that I could craft it into a full-fledged story (and not just a vague idea). If I hit a wall immediately, I know the idea was just that - a passing fancy in the wind. And I don't record it, because if I'm not even interested in following it down the rabbit hole for five minutes, I sure as hell won't be able to write and edit an entire manuscript about it. But if I can follow it for more than five or ten minutes, I'll open a new Word Doc (or Google Doc, depending), and write down everything I can think of.

This file is usually a mess of bullet pointed ideas, short snippets of scenes, character and location listings and their descriptions, and links to initial research if I need it (I'm into period pieces). I don't restrict myself on what I write, so long as I capture everything I thought of in conjunction with the idea. This helps me later on if I do eventually return to the story idea, because it's usually the cute/clever little details that I forget when I sit down later. Or, I solve my problem from the beginning and forget what I decided I would do.

And if I'm in the middle of something else, that's where the brainstorm ends. I don't let myself get sidetracked, I don't start writing from the beginning (I'm a very linear thinker and writer), I just capture the storm of ideas and then save them later for safe keeping. And if they're interesting enough to write about, I can't stop thinking about them until I have to go back. If they're not, I haven't wasted 50,000 words talking about them.

So how do you capture ideas? Where does inspiration strike you? Do you have a methodology that's more organized than mine (PLEASE share if you do)?