Pull your ear to stop a cough.
Look at something dark to resist a sneeze.
To stop a cough: Pull your ear straight out–away from the side of your head. It works like magic! (Thanks, Renee`)
Avoid a sneeze: Look away from the light at something very dark. Sometimes it’s enough to simply close your eyes.
Aggravate a sneeze, to just get it over with, by looking at something very bright.