Plan long plane rides around your baby's nap or sleep schedule so that she will sleep during part of the trip. To lessen jet lag, start adjusting her schedule a few days before to match the destination's hours.
Make sure you put all liquids (formula, breast milk, medicines, etc.) in the same, easy-to-reach place in your luggage to shorten your time through security. Because security staff must check each bottle of formula or breast milk that you bring, bring one larger container and fill the bottles as you need them once you are through security.
Take a small umbrella stroller with you and have it gate-checked as you get on the plane. The stroller will also be waiting for you once you get off the plane at your destination. For smaller babies, use a sling or a backpack to keep your hands free.
Bring a new toy to entertain your baby during the trip.
If your baby is eating finger foods, bring some with you on the plane. Give your baby a pacifier during takeoff and landing to relieve ears clogged due to pressure changes.
For car trips, install shades on the back-seat windows to protect your baby from the hot sun.
