1. Unless they are your real friends in real life, assume all SC II people who add you randomly as friends as trolls and losers.
2. If you added an SC II player as a friend because you like them, it doesn't automatically mean they like you too.
3. Keep your friend list to a minimum, 1 is too much already. Let them come to you.
4. Backstabbing and stupidity is rampant.
5. Be honest and nice always. It always pays to be honest and nice.