Don't order things you don't understand
"... and then act like the waiter intentionally brought you something you don't like. Make sure you understand what you are ordering. For example: my mother ordering a drink with jalapeño and then getting extra tight with our waiter when it tasted like... jalapeño."
Let the server know when something is wrong
"If something's wrong with the meal, tell us right away. A lot of customers tend to be too shy to complain, so they end up not saying anything until the problem can't be fixed, or they won't say anything at all. If the problem is on my end, or if there's just an issue with the food, I want to fix it. Worst case scenario is you leave a bad tip, never come back, or even tell my boss I suck, so we're on the same team here, most of the time. I want to help you; you want to give me some money."