It's Not Brain Surgery!
It's a fact. Stuff happens, especially in a hectic environment like a restaurant. Without knowing exactly how many people are going to order a certain item on a certain day, you can run out of fresh turkey breast or your famous chocolate 7-layer cake. Without being able to control everything, some klutzy patron may trip and fall. Another may think he left his wallet in your restaurant.
With all these possibilites, how do you keep your customers happy? Thankfully, there are some common sense things you can do to keep most of your customers happy most of the time.
Be Observant. A great restaurant manager really watches her customers. She spots a customer who has left a lot of food on their plate and asks the customer why. She trains her staff to do the same.
Be Proactive. A great manager sees potential problems and solves them before they become big problems. If a customer seems unhappy with their meal, they are immediately given a replacement and/or the item is taken off the bill.
Be Hospitable. Smiling is cheap. Be interested in your customers, not aloof.
Be Detail Oriented. Keep the chairs clean. Don't fall behind on your ordering. Don't let the staff get lazy about cleaning underneath tables and counters, etc.