We are flying for the first time with our boys next month to visit DH's family. They'll be 16 months old. MIL has graciously purchased car seats and pack n plays, so that's less we have to worry about bringing. I'm planning to buy travel booster seats to bring with us to feed them there, and I need to get a travel bag for our double stroller.

Any other big or small must-haves/must-brings for a trip that you've learned are essential? The flight will be a little less than 3 hours and we're staying for 9 days.

TIA!