Can you tell me a creepy psychological trick?

Here my scariest list

If youre in someones view, but they arent looking at you, start copying their movements. After a few minutes, you can then initiate movements and theyll copy you. Cross or uncross legs, play with hair, etc.
If youre getting the sense that someone cross the room is makin eyes at you, go ahead and yawn. If they yawn back, you know who theyve been looking at.
If you have customers coming up to your counter, putting a mirror behind you will give them a chance to see themselves to really see themselves before they act like Karen-like (i.e. yelling at you for things that arent your fault).
Whatever your friend has just said, paraphrase it and say it again. The person who talks to you will subconsciously get the feeling you are a really great listener. Just dont go too far with the paraphrasing thing.
When meeting someone new, when you first make eye contact, quickly raise your eyebrows and let your face fall back to a relaxed smile. It kicks their subconscious into the idea that they already know you and can trust you. It takes a bit of practice though, as timing is the difference between genuine and creepy body language.
Smile when you walk around the office/yard/whatever. People either think you are some kind of maniac and leave you alone (good) or they smile back and make your day.