Extra diapers and formula are a must. Also don't forget to pack medications in your carry-on for quick access. Ear blocks happen quickly and medications packed in the cargo hold is of no use to a screaming child. Make sure you get set assignments together when you make your reservations. Carry a camera on you.
Pilots love to have kids up to the cockpit to answer questions or just look around.
At the end of the flight kids can sit in the seat for a picture. Just don't forget the camera. Hopefully you will find these tips useful on your next trip with your kids. The most important things to remember are to pack light and bring the camera.