#5: Barista
You should always tip your barista, and it’s not just for spelling your name right or for memorizing your terribly difficult order. Baristas know more about coffee than your average caffeinated bear. They even know the technicalities behind what you actually mean when you say you want a stronger cup of coffee.
Expert baristas know that you are looking for a darker roast coffee and not an extraction rate that will keep you awake for three days in a row. They’ve undergone extensive training and could tell you what type of coffee they are drinking with their eyes closed. Don’t mess with a barista!