I think tipping is one of those things to see who is petty and can't sweat the small stuff in life. 10% bad service, 15% average, 20% and above for great service, all on the full pre-tax bill. If your the type who is going to argue on how much effort the server put in, or how much hypothetical markup there is on food or booze items, how spoiled rotten the hot upper-middle class white teenager is and how they don't deserve your hard-earned cash, yadda, yadda, yadda, just plain avoid going out to restaurants or start eating in restaurants that are more in your price/class range.
In North America it's customary for the tipping system to be as described above and the compensation schemes of these types of businesses are stuctured with that in mind. In high quality restaurants where wine bottles are $100 a bottleand up and entrees are $45 usually I find the wait staff are in their mid20s to mid 30s and know a heck of a lot about their menus, winelinsts, and practically wipe your ass. If paying $30 on a $200 meal for two just makes you want to die inside either you don't belong there, it's a special ocassion and you should have already mentally prepared to spend a lot, or you are a cheapskate. Simply don't go.
If the restaurant overprices things and the service is not up to snuff, just pay the damn 10% tip, don't go back, and when the topic of restaurants comes up among friends recommend they avoid it. In time the server and restaurant reaps what they/it sows and doesn't need a "This one's for the little guy getting oppressed by a cartel of juggernaut restauranteurs" 5% or lower tip routine as if somehow one's cheapness had an altruistic component. The latter of which must really make one popular with friends and the ladies!
