Reading, sleeping, watching movies, reading, character creation, world building, reading, etc., etc.
The Book Thief by Marcus Zusak, Les Misérables by Victor Hugo, Jonathan Strange and Mr. Norell by Susanna Clarke, Sphere by Michael Crichton, The Phantom of the Opera by Gustave Leroux, etc., etc., etc.
J.K Rowling, Rick Riordan, Ray Bradbury, William Blake, Edgar A. Poe, Victor Hugo, Agatha Christie, Dan Brown and maybe a couple hundred more ;)