Don't Be Stupid
Coming up with a proper insult that's mean and personal enough to get you blocked by someone but not so ridiculous as to get you ostracized by humanity in general (and Twitter specifically) is an art in and of itself. Any moron with a keyboard can resort to slurs and other wild ravings. And while that kind of thing might land you a prime-time spot on Fox News (peace out, Sarah!), it will also make your Twitter stay real short. Don't rip Magic Johnson for his HIV status—kill him for his Lakers "coaching" career (5-11 #NEVERFORGET) as he bemoans the current team and praises rivals. Study your subject, identify his or her weak points. Then go in for the kill.