A thing I like to do at work is take on customers who aren’t exactly problem customers but whose regular order is so far outside of the ballpark of standard that anyone who has not served them before will not do it correctly and then will be berated by the customer for their mistake. Sometimes I’m even the guy being berated the first time around, but once I’ve locked in to the thing you want, you’re going to get that thing every time you come here and then you’re going to have to be nice because there is nothing left to be mean about. No matter how negative our first encounter is, I can always get things to a point where the customer is happy to see me because they know my presence means their thing will be made as expected without any effort on their part. This frees everyone else on the floor from the mental burden of recalling such information, and they can instead remember things like basic math or the color of their loved one’s eyes.