As for changing my behavior because people may be observing me, I try not to pick my nose in public.

Then there is the opposite tack of always picking your nose in public. It causes adults* to look the other way in disgust and avoid you in general. If someone is observing you, nose-picking is guaranteed to get them to transfer their attention to someone else. It also helps repel pickpockets since the perception is that a nose-picker couldn't possibly have anything in his pockets worth stealing.

Smearing brown shoe polish on the backs of your trousers can have a similar effect. Talking loudly to yourself used to work, but nowadays most people will just assume you're talking on your mobile phone using Blue-tooth.


*The nose-picking strategy does not work with children. They find an adult nose-picker to be an endless form of fascination.