In general you will want to have a handler with you, even if it's just for making up for the limited vision so that you don't keep bumping into things or people.

I may not be the best to really give advice on this as I can be much more forceful when the chips are down and I stand pretty tall overall.

the handler is one of the best answers as they can do more.

If you are solo or your handler is distracted.
- The long arm point telling them to go away sometimes works and can gather attention of people around you.
- Turning and walking away into a crowd or in the direction of a con staff can work.
- slowly shaking your head works with a few because you already have the dead eye stare with the mask.

Do not play demure even if that is your character, creeps are trying to force themselves into a situation and the best way to shake them off is to show that regardless of their desires, you are the one in control.