We have on the wall in our school room pockets for sorting books in both Genre and Theme.
I used these wonderful posters on Beth Newingham's site and added a back page to make them into pockets. Books that we have read, I have run off the cover and had our daughter place them both by Genre and by Theme. I made the covers small but for this year I am going to make them much bigger. They may need to be placed in several of the themes so I just ask our daughter how many copies she needs. Blessings!!