Spacing
There should be sufficient room on each shelf to accommodate the end brace and extra space for book re-shelving. Sometimes a shelf looks almost empty. This can be because many books from that shelf are in use, but often it is the result of haphazard re-shelving. Each collection varies in how much shelf room it has for all of its books, but just remember to leave an even amount of space at the end of every shelf--usually about 1/4 of the total shelf space. Do not crowd shelves or cramp books!