When I was waiting tables, I got paid $2.65 an hour from the restaurant. After tips though, I ended up making roughly $18 an hour. When I switched to bartending in the same place, it jumped to $28 an hour. I depended on tips for a living, but the restaurant I worked at was a special place. Most people went there for birthdays and graduations, they were prepared to spend money on the evening and expected above normal service. I had to wear a bow tie for crying out loud. But I never felt bad about expecting a good tip because, for that place, I always felt it was part of the whole package. Nevermind the fact that I was a fantastic server.
One thing people have to realize too, is that the industry feeds into itself a bit. Back then, after work, we would all go out to neighboring restaurants or pubs and party with other servers and tip insane amounts of money. Often 50%. I once tipped another bartender $30 on a $7 dollar tab. But, remember, when they came into my place, it would come back to me. It was like the nice game or something. I was in a scene though. We all wanted to spend our money like that.
As far as claiming tips. The way that it typically works is that when a server cashes out at the end of the evening, the computer will ask them how much to claim. I would usually do 10% of my sales, NOT my tips. But the decision was always up to me. When I got a check for my hours worked at the end of the week, the goal for me was to have the check be 1 cent. Because taxes would be taken out first, I knew that if my check was 1 cent then I was still paying everything required of me but not a penny more.
Back to tipping: Living in Canada now, I see a much different tipping culture. And I really like it. Tipping is more of a gesture of decency here than a method of support. If I told someone that I was going to tip over 20% they would just say 'why' and presume that it is completely unnecessary and, in fact, a waste of money. But it is true that the service is not even close to what it is in the states. I guess all around, expectations are less about that kind of thing, and I'm alright with that.
Going back home now, I have a much easier time being the less than great tipper. I usually will do 15 to 18%. But my checks are typically higher than average at restaurants too, because I like to have a decent night out. So in the end my 15% on an $80 dollar bill is better than someone's 25% on $40. Also, I do not have any problem with tipping very poorly if the situation warrants.