i use a skill i learned in therapy called mindfulness. it takes some time to learn, but essentially, in therapy we learned that emotions (anxiety and paranoia are emotions/feelings) are very deceptive and can lie to you. they're not meant to be the dictators of our thoughts and behaviours. they can make you think that you're in danger when you're really not. so we learn mindfulness which is just being really aware of whats going on around you, and within yourself as well.
you learn to "take a step back" and observe your thoughts and feelings from a distance, to slightly push them away a bit to dull the intensity and allow yourself to think.
so when i start getting paranoid i take a couple deep breaths, and i focus on letting go of every thought that goes through my head, to clear it out and give myself room to think. and then i think about *why* i was getting a paranoid feeling. and at this point im calm enough that i can clearly think about it. this is when i simply conclude that im 100% ok, im just experiencing an effect of being high, and i let the fear go. and if the fear/paranoia comes back a moment later, i acknowledge that its there, and then i just let it go again. i keep doing that, i keep letting go of the thoughts until they just dont come back anymore.