Ha, you just gotta smoke the right stuff. Sometimes that paranoia is what makes it interesting; reveals the contours of your mind. You get a sense of your personality you never had before.
I get paranoid when I smoke. I've found that some strains do it a lot more than others; I gravitate towards indices rather than sativas, and up strains high in CBD.
I have also learnt to watch the paranoia pass through me without giving in to it. There's a sense of "oh hi you again. Sigh." when it comes.
I do also have the luxury of living in Seattle, where I can buy a particular strain out of a wide selection, instead of being stuck with "whatever my buddy scored".