I stick em on my gun cases or my coolers. The more small customized things you can put on em, the easier they are to find in a crowd/shortly after they sprout legs... A sticker will never keep someone from pawning a cooler or rifle case, but it at least gives me a chance to spot it shortly after it sprouted legs (without accusing 5 random people of taking my stuff just because it looks similar to mine).
Also, super helpful to the police, if you have to file a report, to have some way of identifying it (and if you don’t want to go through the hassle of meticulously recording serial numbers on everything). It's not foolproof, but it at least gives em something. Like it or not, they can't really do anything if you tell em you had you Yeti stolen and you can't provide a way to positively identify it as yours. I'm ranting now, but that’s also why I like to take a small file and deliberately put a few beauty marks in an inconspicuous location.
Don’t worry, I've been called paranoid before, and this won't be the last time.