If you work for tips, hope that your next customer is an older woman. A new study says men and millennials are reluctant to tack on to the bill. According to the data crunched by CreditCards.com, the best tippers are Baby Boomers, who are 23 percent more likely to give to waiters and taxi drivers, 20 percent more for their hairstylists, and 16 percent more when receiving food deliveries. While the study shows men and millennials are a bit inconsistent in who they’ll tip, when they do, they will leave a little more on the table. Younger people will give 22 percent versus 17 percent for the Boomers. Men edge out women 19 percent to 18 percent. Restaurant tips tend to average at around 19 percent for all people, the results say. How much do you generally tip? In which situations will you not tip?