You've heard it many times before: keep a notebook. But do you? If not, maybe you will after hearing why director Guillermo del Toro keeps a sketchbook:
"What's great about a sketch book is, you put drawings in it and then they're there. You carry them with you and consult them and thieve from yourself. There's something about that guy at 28 or 35: he's smarter or fresher than you are at 40 but he's somebody who understands you perfectly, because it's you.
In a sketch book you can distill your compulsions, because I believe every artist is just the sum of his or her compulsions. Keeping a catalog of those obsessions through the years, you steal from someone who is almost electrically alive with those same compulsions at age 21. That makes the dialogue very fluid. I revisit the books before every project."
The same thing applies to a writer's notebook. Of course these days smart phones make it easier to write or record or photograph anything you want to add to your collection.