Our middle school library is tiny. It is really just a repurposed classroom.
We have run out of room for books, especially in our fiction section, so we moved our 2nd & 3rd copies into a makeshift "storage" area.
Shari added a "STO" prefix to all those copies, labeled them and moved them to a cabinet where they are in order, with two rows of books on each shelf. She is planning to have a routine, where she pulls requested books and students can pick them up the next day. We'll see how that goes next year.
In the meantime, the shelves look so much cleaner and inviting.