I worked in the industry while in high school. I worked at the Broadmoor Hotel (Charles Court) and at the Briarhurst Manor in Manitou Springs as a busboy. If you are good and went way beyond the call of duty, you made more than the customary 15% back in the day. My waiter would always ask me on larger parties if we should just add in the 15% which was common even back then.. late 1970's, We NEVER did that because we knew we busted our ass for every customer that came in and we always would be left more than the 15%.
A lot of people have zero clue on what "TIP" stands for.
T - To
I - Insure
P - Promptness
If you are not getting Prompt service, you are a fool to pay them like they did.
PS: I tip my hair stylist 33%, Khan, ask you wife if that is enough
PSS: I was in Greece last summer and they look at you like you are crazy if you give them a tip.