1. Be excessively rude – who’s going to stop you?
2. Swear and curse profusely – some people may take offence but hey, that’s their problem.
3. Publish links to your own website with every update – so what if people call that spamming, you just want traffic.
4. Never respond to messages just say what you have to say – your opinion is far more important than anybody else’s.
5. Make things up on the spur of the moment – nobody fact checks anything anymore, you’ll get away with it for sure.

The point is, there is no such thing as Social Media Etiquette, it’s just good old fashioned Social Etiquette. You are just as free to be a total arse in the social media space as you are in any other social space, you just need to bear in mind that the same consequences apply.