On similar matters, I give larger tips after a haircut eg £14 rounded to £20. He’s a good bloke and I’m in a fortunate position compared to him.
Another thing I did during the lockdowns, people including @Herr Tubthumper mentioned this at the time, was to overpay some services to help them...
Depends on the country. Never if there’s a service charge …. I used to check with waiters that staff receive it all, they did, so I stopped asking.
UK > 10%.
US > 15%
European nations - I check on the individual custom.
Never a tight arse, unless awful service.