Pull every book off the shelf before you start sorting, since organizing in place makes it easy to miss duplicates and impossible to judge how much space your collection actually needs. Decide on one sorting system before you touch a single book, whether by genre, author, color, or size, since switching systems halfway through means redoing work you already finished. Set aside a separate pile for books to donate or sell as you go, since deciding to keep a book you never read is much easier when it's still on the shelf in front of you than after it's already been reshelved. Leave a bit of empty space on each shelf rather than packing books edge to edge, since a completely full shelf makes it hard to add new books later and damages spines when you force books in or out. Store oversized or fragile books flat rather than upright, since standing a large art book on its spine for months can warp the binding and crack the spine over time. Keep frequently read books at eye level and reference books you rarely touch on the highest or lowest shelves, since climbing a stool for a book you use daily wastes time you won't get back.