Not too many things, in fact. It is actually very, very, let me stress it more clearly, very hard to make a Russian crack a smile. What are the secrets to make one show his or her grin? First, of all, find yourself a Russian, preferably untamed. If you are looking for some extra challenge, check out Brighton Beach, those people are famous for never ever smiling. The legend goes that once a person smiled and since then the mysterious illness took over a newborn baby. The baby survived, but that person got banished from Brooklyn forever. So it is much easier to hire foreign students and test your smile-causing abilities on them. They also might be easier to work with than adults. Although they tend to have very little sense of humor on none at all. While writing this I realized that consequences of sharing my secrets with you could be very bad, to put it easily. Besides I could sell those tricks and make some money off of it.