The most basic rule of etiquette: Don't be a terrible human (aka, don't be an awful person, don't be a monster, don't be an existential crisis waiting to happen).
Rule 2: Don't use your 'I'm a functioning adult' as a valid excuse for anything (especially not for not doing your taxesประก).
Rule 3: Don't talk about your 'creative process' unless it's actually creative (or, you know, you're just a mess, and that's okay too, but prophets are usually not that interesting).
Rule 4: Don't use the phrase 'no offense' when you're about to offend someone (it's like saying 'I'm not a liar' when you're clearly a liar, or 'I'm not a cheater' when you're clearly a cheater... it's all just a mess of lies).
Rule 5: Don't 'accidentally' hurt someone's feelings, it's just not worth the 'ประก (just be kind, be nice, or, you know, just be an actual human being, it's not that hard).