Before college, I used to work weekends at a local pizza restaurant chain in Eminence, Kentucky, not far from where I lived at the time (Port Royal, KY) called Hometown Pizza.
Working at Hometown, I picked up certain things that I never noticed before as a customer there. And these things greatly influenced how I act when I eat in a restaurant.
1. Always tip your waiter/waitress, ALWAYS
Even though I was a cook there, I saw firsthand the devastation in the eyes of a waiter/waitress when they did not get tipped.
Waiters and waitresses get paid roughly two to three dollars an hour and are expected to make up the rest of their pay in tips. When you don't tip your waiter or waitress, just know you are the reason they can't pay their electric bill or their rent.
I don't care if your waiter or waitress treated you poorly (which is rare), tip them the standard 15 percent of the amount of the bill.
2. Treat the restaurant like your home and respect it
I can't tell you how many times I was at work and I would always bus the tables after a huge dinner rush and the whole restaurant was a mess.
People would sometimes throw food on the floor and would make a mess of the tables of which they sat. It took a lot of work to get the restaurant clean again after that happened.
Because I had to clean like this before, I always try to not make a mess at my table and when I am done eating, I always stack up the dishes to make it easier for the busboy and the dishwasher to get.
I've done both jobs, so I know how hard their jobs are.
3. Be considerate when the waiter tells you your food may take longer to get out to you
Especially when the restaurant is busy. You are not the only person the cooks are cooking food for. When I would cook pizzas at Hometown (I used to call it slinging' pizzas), our ticket machine where people's orders were coming from was constantly printing tickets.
It's not easy keeping up with orders that continuously kept coming in.
Sometimes, we would run out of ingredients and we would have to run to the freezer to get more. Which adds more time to get an order cooking and out to a person.
4. Always show gratitude and humility towards restaurant workers
They work their tails off making sure you have the best service at their restaurant. Be a decent human being and say "please" and "thank you", you know, basic good manners. They aren't your slave and you should reward them for the work they do.
And in case I didn't emphasize this point enough,
5. Again, TIP YOUR WAITERS AND WAITRESSES!
I can't stress this enough.