Give Me a Receipt, Kind Employee
If you’re unaware, there are such things as mystery shoppers. What they do is they receive jobs to purchase food at restaurants, including McDonald’s, and they rate the quality of the food. Some of them will even measure the temperature of the patty, just to see that everything is up to standard.
One clear giveaway of a mystery shopper is that they’ll ask for a receipt. So, if you want prime service, put on your most professional voice and kindly ask for the receipt immediately after paying. The staff might be alerted that there’s a mystery shopper in the restaurant and work double-hard to make your McDouble double-juicy.