A couple of years ago, my mom, who is a school librarian, went to a conference and was given this massive red book full of blank pages. Although other people at the conference may have had trouble determining what to do with that book, my mother knew just who to give it to: her book-loving, story-obsessed daughter. Sure enough, I unwrapped it for Christmas that year and, in a matter of seconds, knew exactly what I would use it for.
Characters. They're the meat and potatoes of a story. And they're so much fun! There have been so many times that I have been surprised by my characters, and by the end of my books, I'm always sad to say goodbye because they have become so dear to me. So I made a character book, complete with fancy headings and cursive lettering. I've used my limited artistic abilities to sketch out some of the characters included in it (they're not the best drawings, but since the book is just for me, I've decided I don't really care). It's nothing scheduled, nothing I have to get done. Just a little side project.
But let me tell you, it's a good side project to have. First of all, I think it's important to spend time with your characters. The more you think about them, the more likely they are to develop in new and exciting ways. Readers don't want to waste time on flat, stilted characters. They want characters with depth, and characters with depth take time to grow. Second of all, it's inspiring! I have had quite a few periods of writer's block ended by spending some time being creative with my characters. Immersing myself in my story world for a little while really gets the juices flowing. Third of all, it's just fun. Writing should be fun! Creating worlds and characters and creatures is magical! Why not spend some time enjoying it?
So that's my advice, from one writer to another. Make a fancy book for your characters... they deserve it, and you do, too.