For as bad with timing as inspiration is, it's still our friend, regardless. Too, it's important to deliver on your inspiration right away, or at least, as soon as possible. Why?
- Something happened to inspire you. This likely means you're in a "good state" to write. If you can manage it, pull away from your current project and start acting on your inspired thought. Keep a journal and write it down, if nothing else.
- There's no guarantee you'll remember your awesome idea later. And that goes double for still being inspired when later finally comes. Don't waste any of it!
- Understand that inspired thought is rare and wonderful, even if you don't know how to use it right away. Again, write it down. A way will be found.
Sometimes people will come to me and complain of writer's block, but they have a million great ideas "saved for later". Don't be tempted to do this with your inspired thoughts. There's no guarantee of a "later" if you're stuck on the beginning of something! See what ways you can work with your inspired thought right now! When later comes, so will other inspirations, and you can use them, then. I say this too much -- don't fall in love with your first draft, and in a nutshell, this is why.
When inspired thought comes to you, don't squander it! Get a journal and log it, keep thinking on it, and as soon as you can, get writing!