Yeah cashiers are a big clue but also double takes. If you're waiting somewhere or on a bus/train, if people mostly ignore you, you likely pass. If they look then do a double take, it can suggest they see something odd. Might not always be the case for you though, your awesome hair might cause that alone! Lol. Some things do that anyway. I've seen a few double takes at my socks when I'm wearing my Marvel socks and even double takes at my Sheldon (Big Bang Theory) style Green Lantern shirt. So sometimes the double take might be for other reasons but it's one thing I look for. If the double take is followed by them trying to subtly stare, they're probably trying to figure out what you are. Don't get too paranoid though, some people are just freaks...or they may actually fancy you! Haha! If guys take an interest in looking at you, it can be another sign. Guys are mostly oblivious and don't take in surroundings so much, women check everything out more. If a guy keeps looking at you, that could be another hint because it's not as normal for guys but then, maybe he's gay! These are all just maybes, nothing definitive. The best and definitive passes are cashiers, bus drivers, people asking you for time, barbers, etc.