My general guidance is that content should show respect. For readers, for people, for ideas, for truth.
Mostly for truth.

I'm a huge fan of this One Amazing Trick to Revolutionise Social Networks: Block Fuckwits.
https://plus.google.com/104092656004159577193/posts/drLZV8sm7Tq

And yes, sometimes I'm the fuckwit. Mastodon's Mute and Block features are useful, make use of them. I will, and have.

I'm also aware that individual actions aren't sufficient in all instances. But they're a start.