Bassinet 100% if you can get one. Book early - first come first served on most airlines.

Feed during takeoff and landing to help ears. Bring formula/expressed milk pre-measured.

Don't bring car seat unless flying to a destination where you'll use it. Hassle and they're often fine on lap.

Bring 50% more nappies and changes than you think you'll need. Delays happen.

Spare clothes for YOU in the carry-on. Trust me.