Well, I haven't been to one in a very long time. But, when I used to go to restaurants, I often left higher tips if the waitress was cute and the service was good. I don't know what percentage I left as tips, but I remember when I left a tip that was higher than the cost of the food itself once. The bill for the food was a little more than $9.00 (can't remember the exact price). I left a $10.00 tip. That was the only time I left a tip higher than the cost of the food, but I remember leaving fairly decent tips before.