There's nothing wrong with letting out a good sneeze (as long as you cover your nose and mouth), but sometimes you need to be quiet or avoid attention. If you need to prevent a sneeze, you can do a simple trick with your nose.
Photo by quinn norton
While the method you see in cartoons where someone places a finger under their nose to keep from sneezing can work, it's not the only effective approach out there. Instead, Professor Alexander Freiherr at Quora suggests you do something different with your nose:
Squeeze your nose. Catch the part of your nose above the tip and stretch it out as if you are removing your nose out of your face. It should not be painful, but simply stretch out your cartilage, stopping the sneeze.
Keep in mind that this won't clear out the things in your sinuses making you sneeze. So you might still need to sneeze later, but it this will at least postpone it for now. If you feel a big sneeze coming on and you know there's no stopping it, there are a few tricks you can do to at least make it quieter.