Bibliocraft adds a significant amount of storage customization to Minecraft. Anything from desks to shelves to custom chests, this mod gives you a slew of options for holding your inventory and it looks significantly more aesthetically pleasing. If you happen to have an excess of books or maps piling up, why not stack them on their respective shelves? They look similar to standard bookshelves, except they are actually functional.
You can also display weapons or tools or any sort of trophy in cases on your wall. It looks much more natural than simply placing them in frames, plus you can occupy more slots in one block with these cases.