Before you go
Pack a printed copy of birth certificate, insurance card, pediatrician's number, and any meds (in original bottles).
Pre-book a bassinet seat for flights >3 hr (call airline directly; web booking rarely shows them).
Snack arsenal: pouches, crackers, raisins, lollipops for ear pressure on descent.
On the plane
Feed (bottle, breast, or pacifier) at takeoff and landing.
Bring 2x the diapers you think you'll need + 2 changes of clothes for baby AND for you.
Window seat = wall to lean a sleeping baby against.
Road trips
Drive during one nap; stop every 2 hours for a movement break.
Pack a 'busy box' they only see in the car.
Sun shades on rear windows — overheating is a real risk in rear-facing seats.