Unless the waitress is truly terrible and going out of her way to be miserable, she'll get a tip from me. If you have a complaint about the food, let her know. People think they're making a statement or proving a point to the restaurant by not tipping their waitress, when really you're just fucking the waitress.
If you can't afford to tip, you can't afford to eat out.
If you can't afford to tip, you can't afford to eat out.