In any service area, I believe a customer/server relationship is a two-way street. This is particularly true in a restaurant setting; any bad attitude or rotten service emanating from a customer/server goes a long way and can stay with us way after the initial experience.
People who sit down at a restaurant are usually hungry of course. Now when I'm hungry, I can also get very CRANKY if I don't get what I want. This can be in receiving good food, decent service and value. The experience initially starts when I enter a restaurant and I note how my party is seated and how the host/ess treats us. Then it moves along to the server and how they greet us and the degree of knowledge or cluelessness of the server. Then the food is of course the proof of the pudding. The server has so much power to make or break a customer's dining experience. However, let's say the server is having a bad day or just got stiffed from a previous customer. That's going to spill over to their next customers.
From a customer standpoint, I treat servers as I treat everybody else and as I want to be treated: with respect. Even so there are some bad apple servers just as there are miserable customers. That's the nature of the beast when dealing in a service area. But hey it's better than eating in a self-service bland cafeteria setting.
This topic is very timely for me. Yesterday I ordered a takeout turkey sandwich from a gourmet shop. The counter woman was totally clueless if the turkey was from a roast turkey, Boar's Head turkey breast or roll. She also didn't know what extras I could add on to the sandwich. She went into the kitchen several times to check. I noted her tip jar contained about twenty cents. The sandwich finally arrived and it was prepared to my order and I left her a $1 tip in the jar. The woman's face totally lit up and she flashed me a broad smile. She greeted her next customer with much enthusiasm. I know this is a kind of "Play it forward" situation. I guess tipping here was good karma.