If it's a smut-centric fic then I tag everything that's going on, because if I'm reading a porn one shot I like to know if there are any kinks that tickle my fancy or not. But if it's smut in a longer fic, then I don't really tag for individual sex act and tag more for plot things. But then, when I tag smut it's not so much so people avoid things but more to be like "Hey, you like this kink?? well boy howdy do I got this kink for you!"