When do you start discipline and how to do it?

[Smoke Jaguar]

I recommend reading a book called "Unconditional Parenting" by Alfie Kohn as a foundation to your approach to 'discipline'. Also, the Science of Parenting, as well as ANYTHING by the Sears (google them) in relation to anything parenting.
One of the things Kohn says that sticks in my mind is this:
Think about what kind of adult you want your child to be - most people would say independent-thinker, taking initiative, go-getting etc. We tend not to 'train' them this way, oddly enough! We 'train' them to be subservient, not to listen to their instincts, to look for the approval of someone else (i.e. the use and reliance on praise, an external reward, not an intrinsic one) etc. How can the way we 'train' our children result in the adults we want them to be? Food for thought. Kohn goes into it really well.
Rewards and punishments are not utilised in my house to elicit desired outcomes. Love, modelling and sharing (verbally) the value in doing things a certain way are what we use

[Rouge]

I have done exactly what Sarah does for the past 6.5 yrs and its worked marvelously. Paris is an awesome kid (I know I'm biased ) She speaks her mind and knows when to be respectful. We have a very open and understanding relationship. This morning she even told me about how a week ago when she'd asked to take a delicate ornament to school for show and tell and I said no, that she was going to sneak it into her bag, then she thought no I better not if it breaks then I'll feel really bad (which was my reasoning for her not taking it). I praised her for her honesty and I said I was proud of her for making the right decision and glad she felt comfortable telling me. So I dunno I look at her and I'm proud of what I've done (and there isn't much in my life thanks to my crappy self esteem that I can say that about). And I look at Seth who is a handful and he's already following in his sisters footsteps even if we've had to tweak it a little I think communication above all, understanding of temperaments and not treating them like stupid adults all leads to well rounded children. Consistency is important but consistency also applies to adults to in this house. If we do something that upsets her and she has asked us not to do xyz she has just of a right to be upset and express that as we do, and it is up to us to try and find a solution to resolve that, and work out a plan to prevent it in the future with her as we would do in reverse. Its not just about discipline its the entire package.

ETA: It crashed and didn't save the last line... grrr... What I said was IMO boundaries don't disempower children (and I'm not talking discipline here) but its about the entire relationship you have with your child, as that can.