Especially because you have a crawler, bring a sheet to put on the floor of the airport in case you have a layover. My husband and I neglected to do this and ended up wearing a very angry 9 month old all day long in the Philly airport when our flight was delayed 8 hours.
Nurse on takeoff and landing if you can to prevent ear pain and don't overload yourself with toys. Our daughter played with ice and a plastic cup for most of the flight.
We also really like those food packets for easy meals on the go without mess.
Change diapers before you get on the plane because otherwise there is literally nowhere to change a diaper. I did it on the seat of the toilet and it was a disaster.
If you don't already have one, find a comfortable carrier you love. Messing around with a stroller and luggage would be terrible.