the best way to reduce paranoia is being in control of your own mind. If you can manage to be clear-headed enough to remember that nothing in the world is different than it normally is, and that it's only a matter of your perception that is changed then you should be ok. It is easy to believe that people are staring at you because when high it seems like they are when they're really just looking at you normally. (or perhaps not, due to your behavior but whatever) If you start to get paranoid just close your eyes for a moment and clear your head of thoughts, then remember that you're high and everything is fine as wine!!!