Writers have a variety of techniques for sorting out the stories that run riot in their heads. I know one who allegedly wraps a roll of wall paper all round the room and plans the whole thing on that. Post-it notes, in various colours, are very popular. One of the more artistic ways is to make a story board. An author will collect pictures - hero, heroine, the dog, the perfect cottage, the car ... you get the idea - and put them together like a collage. It always looks like a lot of fun, although I'd worry about getting a bit obsessed with collecting, rather than writing. That comes under the heading procrastination, and we all know how authors love to do that!
I don't use pictures of people, my characters usually arrive in my head without that, but I'm wondering about doing a bit of story boarding of things and places for future books. I already do it in a small way, as I have a bag of odds and ends that are going to fit into a story sometime, but they tend to be written stuff, not visual. I like to create location tours for books, but those are usually done after the book is written, not before.
Which gives me plenty of time to collect some more pictures to make a board.
Maybe I've started something here?