Peronally, I hate being felt required to leave a tip, but that of course is from the customer's point of view. If from what someone has told me is accurate, in some other countries (Australia for example), tips are not expected and that it's actually the exception to leave one.
For me, I always thought of things as 15% (of the after tax total), so no there's no way think that you're being "cheap". But honestly, we've usually done something even $10 or $20 on a $50 check. That's probably overpaying but sometimes, it just seems simpler to leave an even amount. Then again, me and friend of mine also have done someting equally cheap and bad in the sense if we feel that we've been ignored the whole night, or if we have to ask 2 or 3 times for the bill, and even have to go as far as asking a different server for our bill, we have left 1 cent tips (not regulary, but maybe 1 or 2 times in a 5 year period).
I think that it gets a little more complicated if you become a regular at a restaurant. If you normally give 20 to 30% tips, I think they come to expect it, and if you suddenly leave only 15%, they think they've done something wrong or that you unhappy. In reality, sometimes, you just can't afford to be giving a higher percentage each and every time.
Some of the larger companies and brands (including frachises) forbid employees from taking tips.
