Here's one where I'm sure we can get fifty-thousand stories. Beware of people giving advice. The ones who are quickest to give it are the ones you shouldn't listen to.
Look at other peoples' kids. When you see a kid acting the way you want your kid to act, talk directly to the primary care-giver (traditionally mom, but more and more dad or the Mexican nanny) about it.
The quickest advice will always come from the dad who has nothing to do with the kids and those will also be the kids who seem to be a totally lost cause.