I used to always like, re-MV and everything everyone who did mine right back. But it turned into a full-time job and started getting really annoying. So now I like posts back when I can, for people from here, who I like. Then I leave the rest. When you don't do it back, they simply leave you alone. So it's really up to you what you want to do. Personally, I don't want to log in every day and have 100s of likes I feel obliged to return (which is literally how bad it got), and I don't want my MV social feed so littered with re-MVs that no one can find my own content. So I stopped participating in that. But it's totally up to you.
Plus I don't mind interacting with models from here who I chat with already, but there are lots of models whose content I don't actually like, nor want to like nor re-MV (or sometimes even look at if I'm feeling preggo nauseous or squeamish). However, when they go through and like mine I feel socially pressured to do so back when I really don't want to. So I gave up on it. It really got extremely stressful. I try to do etiquette stuff here on ACF, but I learned over the course of 6 years camming that it really doesn't work out too well for me on the actual selling sites. Never feel pressured out of etiquette to do anything that you don't want to. Members and other models will totally use social pressure, and it's best just to blow it off, and only do what you are comfy with.