1. First, confidence is everything. To seem worth a second of anyone on any board, you have to make yourself out to be better and more interesting than the masses.
2. Don't make threads that beg, look desperate or ask for NeoFriends. You'll only attract people as sad as you and repel people who follow to the point above, unless of course they come to your thread to make fun of you.
3. Don't act clueless unless in sarcasm. And learn how to detect sarcasm and jokes; these are skills that will save your life/reputation.
4. Know stuff. Read a book. Know basic history, math and science. It'll make you more interesting and give your comments and replies some value and depth.
5. Act nonchalant on the boards. Don't act like you give a crap about the forum rules, but follow them to keep your account from getting frozen or suspended.
6. Make sure your font and signature is pleasing to the eyes. And keep it simple, silly! Don't try to make it all dark and gloomy, without taste.
7. Don't try to be something you're not. You'll get a lot of flak if some calls you out, you poseur.
8. Don't call yourself Goth, Emo or Punk without looking up their real definitions on Wikipedia/Fourfa. You don't even have to listen to the right bands; just know them when they're mentioned.
9. Learn to type correct English. 'Nuff said.
10. When in an argument, don't role-play....