There is NO appropriate way to prepare children for an environment in which agents of their own government will be screaming in their faces about laptops in shoes, holding a hand in their face, and making their parents and guardians feel threatened.

This is an environment that is profoundly intimidating and anxiety-producing for adults, and this will certainly rub off on their children.

Children have some of the best BS detectors of any segment of the population. They will see right through you if you say, "c'mon, it'll be fun!"

Someone will probably chime in and say, "But it would be worse for children if there were a hijacking." Well OBVIOUSLY. DUH. But I am convinced that effective screening can be conducted politely, in a dignified and sensible fashion.

For now, the best move that parents can take is to protect their children during screening. It's the same common sense that would apply anywhere... Do not allow the TSA to separate you and your child, and do not permit any screaming or swearing at your child from the TSA. If you're in a line with your kids and an agent is screaming at you, holding a hand in your face, or using foul language, I think it is very appropriate to reprimand the screener politely, pointing out that you are travelling with your family.