i'm basically civil and mostly unavailable to shit family. it's tricky if you need their support, less so if you don't. i also moved further and further away and got off social media, so they no longer have low-effort mechanisms to inject themselves into my life. remove the low-effort ways to fuck with you and be amazed out how many assholes fall off the radar.
if i am trapped at a function, i grey rock them. if shitty people had any shame they would be embarrassed at how effectively they are led away from those of us playing at being uninteresting. people like this thrive on getting reactions out of others. it's like they feed on the dynamic. take that away and they starve.
if somebody reasonably needs something from me, i quickly get it to them without fuss but don't engage in any idle chat or banter. kind of like how i would deal with a shitty colleague or professional associate. maintain basic functionality, but leave them nothing personal to pull on.
i only get into struggle sessions with people i want to fight to keep around. bozos aren't worth my energy.