Off the top of my head, on the run....
I read a lot more than I post these days. I don't feel the need to contribute to some threads which I find really interesting (like I used to) when I know heaps less about the subject than the contributing posters.
I used to become very upset by rudeness, overt & unnecessary aggression & personal insults. When directed at me or at other posters. Now I tend to just thumb down such comments & move on a lot more easily.
Ditto with posters who attempt to deliberately derail a thread discussion by continual trollish posts which have little to do with the intended discussion. I rarely read their posts anymore. I already know what to expect!
I'm finding it much easier to walk away from threads I've initially been very involved in when they go completely off the rails.
I'm much more selective about which threads I read or participate in now. For example, some posters (like boomerang & quite a few others I could name) are always good value & have thoughtful, interesting things to say & I'll always check out their threads & comments. On the other hand, I think I know just about everything I need to know about the oppression of white men by "feminists", so there's no need to explore any further.
I'll probably think of more things to say later, but this will do for now .....