DO insist on your children eating lunch before leaving for the airport. Even when they whine that they're not huuuuuuuungrrrrrrrrrry, force feed them. They will be hungry the exact moment the plane is in the air.
DO NOT under any circumstances catch the 4:30 plane for a four hour flight. This means that they will miss both naptimes AND dinner.
DO NOT travel during a snowstorm. Your plane will leave an hour late and you will have to wait an hour for your bags. Then drive two hours to your in-laws.
DO NOT travel when your 2-year-old has an ear infection. And diarrhea. And an angry diaper rash so bad it actually screams expletives when uncovered.
DO NOT get on a plane with said 2-year-old when said plane does not have a diaper changing table. Nuff said.
DO make sure your portable DVD player is charged. That way, when you promise promise promise your children they can watch a movie, you can actually follow through.
and above all ....
DO NOT travel with children.