As a writer, I get ideas for stories all the time. Characters, bits of dialogue, a flash of a setting. Obviously I can't keep them all straight in my head or remember them all, so I need to keep them organized.
A lot of my inspiration comes late at night when I'm trying to fall asleep or while I'm out running. In these moments, I reach for my phone and open my notes app. It's filled with little bits and pieces to use in future stories.
Once I'm ready to sit down and actually write a book, I grab one of my trusty notebooks...spiral of course. I'm very particular. I have one notebook per book that is just ideas. I flesh out plot, character sketches, and bits of dialogue. I refer back to it while writing, and double check during editing that I've included everything I want. It's often fun to look back and see where I originally intended the story to go, and where it ended up. It's often very different!
So that's how I organize my ideas for stories. What about you?