20% but as high as 30-35% if they do a good job.
I have a lot of friends that are bartenders and waitresses. I appreciate the service I get and enjoy giving them a few extra bucks.
In return, if I am hungry and the kitchen is closed, they might make me something anyway. I get better pours when I order drinks, and never have to wait for them. At last call, my friends and I always can get "one more" if we want, even if last call has already passed.
I don't know why so many people here don't understand that tipping well has its benefits. Waitstaff and bartenders remember who takes care of them, and the next time you see them, they are happy to go the extra mile to make sure you are happy. If you don't want to tip, don't. But don't get mad when you are standing at a crowded bar, trying to get the bartenders attention to order a drink and I walk in and I am served before you.
When I go out for dinner, I like being treated well, and I know that in life you have to reward people that do that. I guess in a perfect world everyone would run to their job and be excited to make everybody's day as great as they can. But, unfortunately, that is not the case.
I don't care how anyone else tips, all the cheapskates make me look even better.