Never compare.


Never show favoritism.


Tell them all you are the luckiest Mommy or Daddy in the world, to have (however many you have) such wonderful children.


Tell each one he/she is "my best (age)-year-old in the whole wide world." (Unless you have twins. Then you can just use their names.)


Remember to say "please" and "thank you" to your children - treat them with the same respect you want them to show.


If (when) there is an incidence of aggression, pay attention to the "victim" first.  Do not reward the "aggressor" with attention.


If there is rudeness, ask "How can you say that nicely?"


Great book:  Raising Your Spirited Child  


Visit my website for more tips.  www.kathleenspalding.com