Waiters/waitress' at nice places make a LOT of money and do you know what they do? They set tables, smile, say a few words and carry plates. OH and dinner is typically provided, free.
I don't mean to make it sound simple but frankly.. it is. Any fairly attractive, charismatic person can do very well as a server... education matters zilch. And the money is good.
At a decent place they'll make $20 or so per table while making $7-8 an hour. Figuring an average of 6 tables a night (which is obscenely easy to deal with) and 5 8 hour shift that's over $31,000/year for a job that requires no particular skills, training, education, etc.
Plus, guess what..? Cooks rarely get paid significantly more, BASE, than servers.. and we don't get tips.. even though the food is the most important part of the experience.
I love servers, they're part of the dining scene and essential to it.. but please don't mistake them as having a hard break.
At a diner or some crappy place, maybe sorta, but at a fairly decent restaurant or club it's a cakewalk.
If you ever want to make easy money and are fairly attractive and charismatic, go apply for a waiting job at a country club. I work at one now as the lead cook/pseudo-chef and it destroys me how much money uneducated, pretty stupid people make on some nights. For holidays and events, which are a common occurence, they often pull in over $200 from tips alone. And these are people that didn't go to college. Don't have any skills. Aren't smart. Hell, they really aren't attractive or charismatic either (save one? and she makes crazy cash.)
...Sorry, got off subject!
I tip 20% for good waiting, 10% if it wasn't very good and nothing if they really mess up. After all, it's a tip... don't tip if they don't earn it.