Hi charlene, the most effective key really is not just to be her mom, but be her bestfriend as well....
i'm not yet a mom so i cannot give advise on a mother's point of view
but i can talk by experience, having been a teenager myself once....

I was really close to my oldest sister growing up, she's like my surrogate mom,
She pretty much guided me on what i should and should not do and what are the consequences of every action i make...
She taught me how to make the right choices in my life and never stumble on the bad ones and regret the consequences....
but she never forced anything on me, not even once....she gave me the free will to make up my mind and my own choices,
she trusted me and my judgement, knowing fully well that i took her advises at heart....
she established a trust, a bond and an open communication with me and i pretty much can open up and tell her just about anything, like a bestfriend..
and i know that no matter what, she will never judge me and that i can really trust her....
and most of all, she made me feel so loved and i felt so secure that whatever happens, she's the one i can run to and count on
and she will be the first person to pick me up if i fall and be there for me for comfort and understanding, if i fail and mess up.....

And it really worked as i pretty much have been a good girl growing up, in a sense that i never got involved in any rebelious activities....
nor party with friends and hang out with the wrong crowd in my teen years and even in my college days....
I never had a bf until i'm working already and mature enough to handle a relationship...
And i chose to follow everything she told me, because i know it's the right thing...
not because i'm afraid of her as i was never brought up in fear, but because i know how much she loves me
and i love her so much that i cannot afford to hurt her, disappoint her and break her heart....
coz i know, whatever mistakes i make and suffer, she will suffer just as much....
and whatever i do that will hurt me, she will be hurt just as much or even more...
and i just cannot bear that thought....knowing that she only wants nothing but the best for me,
so why should i mess it up when i know better already.....

So i can say, i pretty much lived a sheltered life and always "played it safe"...which others may find boring lol, but i definitely got no regrets...as i turned out ok, lol.....
she inculcated in me all the values i carry with me until now and molded me to be who i am....
My teenage years may be too safe and less fun and exciting, but it was all for the best...
and if i'll have a chance of a do-over, i will never do it any other way......
And this is exactly how i'm gonna raise my kids in the future

Being a teenager is a difficult period, it's a phase where you are trying to form and find your identity
and isn't it great to be with your daughter to witness and guide her well, in her transformation......