I prefer to rule with an iron hand and tight grasp on the pocketbook. Allowance starts at 20 bucks and the slightest infraction causes loss.

They straightened up in a matter of weeks.... about 3 if memory serves me correctly.

The problem isn't that they are teenagers - the problem is that they were not trained properly before becoming teenagers. Children crave and thrive with solid discipline. It's the only way to go.