Where do I start?
I also think a lot has a lot to do with the parenting. Disciplining kids takes work, and you absolutely must follow up with what you say...or you lose your credibility.
When your kid does something wrong, its best to talk to them and help them understand why its wrong and then explain the consequences. So they learn the principal of cause and effect...
The hard part comes when you have to invoke the consequences. It takes a lot of time, patience and will power to see it through.
Say your kid breaks a house rule and stays out past their cerfew...you tell them that they cant go out with their friends for a week...you better make sure your significant other is on board and they dont get to go out with their friends for a week.
If 3 days pass and you cave in and let them go out with their friends because they said they were sorry...it sends a powerfull message that Mom and Dad will get mad at first and cave in later on so why worry about it.
Kids love to play both parents to get what they want. Mom says no but maybe if I ask Dad then I can do what I want...Mom and Dad need to communicate every decision before giving the kids an answer so this kind of situation doesnt repeat itself.
I also think the kids need to help around the house and do chores. They should do their own laundry, keep their room clean and pick up after themselves.
Too many parents let their kids do whatever they want and pick up after them...they dont learn responsibility from that.
Kids should also be required to work for anything they want. Want an X-BOX? Well mow some lawns or wash some cars to earn the money. Giving your kid whatever they want isnt teaching them anything but to be lazy.
When you actually work for the things that you have, you appreciate them more and are more likely to take better care of them.
Bottom line: Don't be a "Cool" parent and give your kids everything.
Make them work for the things that they want. When they screw up, take their prize possessions away till they pay the consequences.
Eventually they understand and actually become responsible adults!