So this is a very minor thing, on balance, but I see it enough to think it’s worth saying. In the realm of practical advice: if you have to insert a word or phrase to indicate that something you’re writing means something dramatically different from the surface meaning, you’ve already failed and should try again. What I mean is people going “/sarcasm” in a Tweet or “(irony)” or “just in case you can’t tell, I’m exaggerating for effect” or similar. Explaining it will undercut any stylistic or rhetorical effect you’re trying to achieve anyway, and it’s frightfully inelegant.
I always think of Homer saying “in case you can’t tell, I was being sarcastic,” and Marge saying, “well, duh.” When you explain verbal irony, either it’s a “well, duh” moment and you don’t need to explain it, or you haven’t achieve it in the first place. I would argue that this is true regardless of context and means of delivery. So you’re writing a Tweet and you’ve only got 140 characters? OK, so achieve what you need to achieve in those 140 characters or change your sentiment. Pay attention to context, recognize the restrictions of whatever media you’re working with, and work your craft a little bit.