Advice from "A Guide for UW–Madison Students: What You Can Do About the Flu." (PDF.)
Sleeve-sneezing... learn it before you have sneeze. And quit touching your face.
May I offer a piece of advice that is not in the flier? Don't touch doorknobs. Outside of my own house, I never touch doorknobs. How is that accomplished? Well, again, your sleeve can come in handy — but not part you use for sleeve-sneezing. You can also use gloves, a paper towel (when leaving a bathroom where you've washed your hands), or wait for someone else to open the door (when they are pushing out and you need to go in).