Is There A Right Way To Raise A Teenager?

ARGH!!

I've never raised a teenager before.  It seems pretty tough.  There are mood swings, power struggles, tantrums, fits, loud music... some of that is me.
I am losing my mind.  One minute she is happy, the next she is vicious and rude.  My boyfriend thinks he knows what to do, I know I don't know what to do and we argue about it.  He went barging in her room today and I flipped out on him.
"Don't you dare barge in her room like that!" I yelled and slammed the door to continue talking to her.
I came out of her bedroom finally and he was standing there and gave me the finger. 
So I think... how many children am I dealing with here?
I have learned some things in dealing with a teenager for the short time I have:

1. It is important to deescalate the situation. The louder you yell, the louder she yells.
2. Arguing does not help. It will take you down a losing path.
3. Threats like "you're grounded for a year" are pointless. You can't follow through on it, so you've played into her hands. 
4. When all else fails, go for a walk or a drive so you can cool off. 

It's tricky, you know? I have known parents who went strict thinking it would work and it didn't.  I have known parents who went slack thinking discipline was a "no-go" and it didn't work. Is there a happy medium? What doesn't help is having someone else in the household giving me hell.

• Do you struggle with a partner about parenting technique?

• Is your parenting style different from your parents?