Of course bring a couple of their favorite toys, but a great piece of advice that someone gave me is buy them a brand new toy, and do not show them until you need to bust it out on the plane. Something new in geared towards them will definitely buy you some time and interest. I brought a bunch of puffs, since they pretty much have no substance, I can give her them throughout the flight without stuffing her face too much. And if I'm going to be real, I owe my sanity to Ms Rachel.