Decades ago, I put bright neon yarn pom-poms on all the handles of our luggage, including the carryons because ... gate-checked hand luggage. Initially, my Hubby snarked and made fun, but over time he started asking me to put them on his new bags. The last few trips, I added a bright orange duct tape letter to the front and back sides of our checked luggage. It really helps identifying ours on the carousel, now that other people have added the bright color pompoms to their handles.
After reading this topic and seeing all the bags over Xmas standing upright at Southwest airlines' unclaimed baggage, I'll add some duct tape to the narrow sides and tops, also. Our suitcases aren't cheap and I'd hate to lose them and everything inside.
I also like the Air Tags idea and will implement that before our next trip.