After 17 years of being a mom and a pediatrician, though, I've been able to learn a lot about discipline from my own experiences, and from other parents. While there are all sorts of possible blunders (like the time I forgot I'd left my daughter Natasha in time-out), here are five biggies that most of us are guilty of -- and ways to avoid these common mistakes:

1. Thinking that one style fits all

But some children freak out when you speak to them sharply, while others are unaffected. Some learn the first time you tell them something; others need so much repetition, you despair of their ever learning. Some listen right away; others need time to scream it out before you can talk to them.

And it's not just temperament; it's age and development. The job of a toddler is to push limits, to do crazy stuff that you've told him time and time again not to do. The job of a tween is to start asserting her independence from you, in sometimes obnoxious ways. And neither one is going to listen to a big lecture. A toddler is going to need simple, direct, quick discipline. A tween is most likely to respond to a punishment that removes her from her peers. But despite your best efforts, both the toddler and the tween are likely to keep doing the same bad thing for a while. Understanding where they are in life is key to picking the right approach to discipline, and preventing desperation (yours).