...at the one (Thai) restaurant where I work now:
1) A (thing) (late 20s) (female) (Chinese) student who gets the lunch special and brings her bill to the counter and ends up leaving a $0 tip.
2) Two (younger) (Chinese) students with (dull) and (nerdy) eyes who order four dishes for just the two of them, and say to bring the free salads when they find out they're free but then don't touch them, and who each also get a beverage and who order dessert when we let them know we're closing, and then leave a $2.30 tip on like a $72 bill, and when we're trying to get them out the door and they've packed up some food the one asks me to get her a plastic fork and spoon and I ask if there's anything else for the table and they say no, and then I bring out the plastic fork and spoon for her and like right away the other one asks me for a plastic fork and spoon too, so I talk very clearly and am like, "Do you need anything else? Please let me know now, because I asked you before if you needed anything else, and you said no, and now you need another fork and spoon," and I also ask if they're done with their waters and pick them up, and between all of that they seem a little shocked, and after they're out the door I tell my one (chubby) (Thai) coworker that I feel a little bad because it's business for the restaurant but that's weird behavior to keep asking someone to run around like that after you leave such a bad tip on such a big bill, and she shook her head no, like I shouldn't doublethink what I just did with them, and she said they don't understand tipping yet, they're (Asian).
3) A (late 20s) (STEM-ish) (Asian[-American?]) repeat customer who is wearing (gigantic) headphones and who has had weird behavior before like ordering to go and then sitting down at a prime window table upfront and asking us to bring him water, who comes in and orders his usual vegan dish, and who keeps walking out to talk on the phone or do something out there even though the restaurant is closing soon, and my one (chubby) (Thai) coworker asks me if he knows the restaurant is closing and I tell her that I had asked him if he wanted any dessert because the kitchen is closing soon for the afternoon, so he should know, but when he keeps going outside and his food isn't really eaten much, she steps outside to tell him, and he says he didn't know that the restaurant is closing, and he gets to-go boxes and comes up to pay the bill at the counter and and hides the receipt he signed, which has a $0 tip.
. . .