I also make sure to use the space on top of the bookcases. If you get stackable totes and organizers, you can make the most out of the space that you have. You can also put pictures on top, which adds a nice ambiance to your room.
I hope that my shelves provided some inspiration for you! There are great resources out there for how to organize your shelves and StumbleUpon and Pinterest are good places to go to for bookish inspiration. Happy shelving!
Theresa