My dad has always told us that if you go out to eat, you leave a 20% tip, unless they were horrible. And extra if it's a special day like Christmas Eve. Tipping is part of eating out. If you can't afford to tip then you can't afford to eat out. Plain and simple.
Do you often find that there is a certain demographic of people who don't tip? I ask because I have friends from other countries who don't understand the concept of tipping, so they don't. One of my friends is from Panama and it took him two years to understand that you are supposed to tip at restaurants. (whenever we went out to eat with him, we'd always have to cover his portion of the tip since he would not pay it. I'm glad he finally understands it now.) Apparently it's not something they do in their country. I know that NYC and the surrounding areas are extremely diverse and abundant in immigrants, so this is why I ask.
Also, am I the only one, when tipping, I have to round to the nearest whole dollar? Say the total, with tip, comes to $13.38 - it has to be 14. I just like seeing whole numbers on my credit card statement, I'm sorry.