A few ideas about who to befriend and what to do with them...

1. Never apologize for who you are. Trite? Yes. But if you're hanging around people who make you feel like you need to pretend to be someone else, you're hanging out with the wrong people.
2. Never make someone else apologize for who they are. Save yourself the trouble. If you constantly find yourself picking someone apart; if they drive you crazy, don't torture them or yourself. Spend time with people who you can celebrate!
3. Don't act or speak if you feel jealous. Good people do horrendous things when they feel the heat of envy. Envy destroys rationality, good manners and, inevitably, friendships.
4. Don't suffer fools. Period. There is nothing admirable about tolerating someone who offends any of your true senses: justice or right and wrong. Stand up for the things that are worth fighting for, and don't waste time on people who make you fight about the asinine.
5. Don't pick friends who are just like you. One of you is enough! People who compliment us are often the people who do what we cannot, or who cannot do what we can. That way, they lift us up and we lift them up; we teach and are taught; we grow in ways we wouldn't if they were not in our lives. 
6. Love hard. Don't be distant for the sake of being cool. Love true and hard. The people who matter won't push you away. They'll be glad to have you.
7. Don't play games. If you're mad, say it. Say it when it happens. Get it out. Emotions grow exponentially when you suppress them. And suddenly, something as simple as "you hurt my feelings" becomes "you always hurt my feelings because you're selfish and vapid and I hate you." Seriously.