Maintain an internet presence you believe to be private. I first learned this lesson with a LiveJournal ten years ago in which I cataloged in detail my attempts to call my ‘boyfriend’ who wouldn’t call me back, and all the ways I had tried to conceal my identity whilst calling. Turns out some girl from my class who was not my friend had reported it to him and the two got a kick of out every entry. Other lessons to learn: don’t talk about someone blowing it in his pants when you made out at a gay bar if it’s possible his girlfriend can find your internet presence, don’t muse about how you want to murder your roommate (she will not care about the irony).
Send an innocuous and/or decontextualized public comment to someone your friends and/or followers will have an opinion about. This includes writing on the wall of and/or tweeting an ex-boyfriend or girlfriend, a friend you’ve had a falling out with, or a celebrity you’re unironcally trying to get in touch with.
Make reference to something ‘no one has ever heard of.’ This will either piss off non-hipsters–who haven’t heard of such thing but are responding on principle–or hipsters–who have heard of it and are offended you are suggesting they’re ignorant. I once idly tweeted something like, “Does anyone want to go see Zola Jesus; none of you know who that is, do you…” as a sort of earnest, self-defeating message to brace myself for when no one responded, and six months later people are still giving me shit about it.
Use an un-PC term in a relatively innocent and/or non-malicious way. Generally speaking one ought to apply the principle of charity when interpreting what their friends have to say. Public forums are tricky because not everyone knows you well enough to be charitable about what it is you’re saying, but whether people should or shouldn’t be offended by what you say, this is a great way to start a shit storm.