OMG. An amazing thread, and fantastic posts. All of them brilliant, esp JaceLancs.
My DD is only 13, so I'm not qualified to comment, but my DDad's mum always used to say "well, you just cross your finger's and hope" and my mum used to RANT about how "smug" she was, but I now I'm a mum, I kind-of get what my grandmother meant, because it's the "unbearable lightness of being" (if you know that book) - you do your best, and you don't know until the finished product whether you were right or not.
But I do think there are some do's and don'ts.
My DH always says "you can't love them enough, and you can't give them enough confidence".
The people in my life as an adult who ARE the most confident and sorted are those who were ADORED as children.
So I think that is right. I think you have to love them beyond all reason, and for them to have to know that.
I also think that children want and need to feel safe, so you have to give them boundaries. And these are up to you. Whether it's how you cross a road or a tidy bedroom, I think children need to know where they can feel safe. It's up to us as adults to make the safe spaces appropriate. And for them to know they can not/should not cross that boundary.
The people who've said upthread "pick your battles" I also think have got it spot-on. Don't criticize your child every 30 seconds... decide what is important and go for that.
Don't do "punishments" (they don't work!) but do "consequences" and make them appropriate (in terms of time and to fit the "crime"). And make them 'time-limited" (I know parents who boast "he's grounded for the next 6 months" - that is ridiculous and impractical: Make it something you're prepared to carry out)
Praise them. You can never do it enough.
DON'T go to bed on an argument - let them know that you love them, even if you hate a behaviour or choice they have made.
Be honest. Including saying things like "I hate that, but it's ok if you like it: I hate it, but it's your choice".
Let them make mistakes and learn from them.
Be consistent - don't threaten if you aren't prepared to follow through and DO follow through - make yourself reliable (that's part of the boundaries mentioned earlier)
And BREATHE.....