Genre, then alphabetical order....for example, jazz, blues, rock, disco, military marches, soundtracks, disco, easy listening, classical, country, folk, etc. Have MOFI separated on their own racks, as I do Nautilus, DCC, Simply Vinyl, Etc. It’s a long process and is still something I am trying to keep up with, but the occasional flea market, record store, or on line purchases are accumulating faster than I can sort. And, coworkers, family, and friends who have given me boxes of records, I am still sorting those as well. In Germany, my old neighbor gave me a box of classical Deutsche Grammophone records.