Do not swear
To use good netiquette you should not swear the reason being is because they can trace it back to the bully that wrote it.
If you write in capitals it seems like you're yelling or shouting at the person that is reading it.
Don't think that you can browse through other peoples files without permission because even if you use another name they can still trace it back to you and you will get busted.
If someone posts something that your not interested in, don't reply and say rude or offensive things to them or family.
You should not share personal information(passwords, phone numbers and credit card numbers)because people can pose as you and say hurtful things.