@FlyingSaucer @technomancy I'll give you a short list.

Don'ts:

• Don't be an asshole
• Don't be racist
• Don't be sexist
• Don't be homophobic
• Don't be transphobic (including the famous "I'm not against trans people BUT..." No. Just no.)
• Don't be fatphobic, ableist, don't do victim blaming, etc.
• Don't be a nazi. No hate speech, no slurs, no conspiracy theories about minorities erasing white Americans or something.
• Don't be a reply guy. While it's not a bannable offense, that guarantees people will mute or block you pretty fast.

Dos:

• Use content warnings liberally. When in doubt, use them. Nobody will complain for using to many of those (unless they're an asshole).
• Try to add descriptions for images. If it's a screenshot and you're too lazy to type in all that, add a CW for image without description.
• Try to respect others.
• Have fun!