Did you know that most wedding vendors expect to get tips just like any other service? In the United States it is customary to give tips to service professionals, and the wedding industry is no different.
10 to 20 percent is a nice way of saying "thank you". So lets say your bill for the makeup is $500, then you should give them a minimum of $50 or 10%. If you are really hard up for cash, or booked a very expensive honeymoon, then leaving a Yelp or Google review would also be a nice gesture.