When they were smaller, we always booked bulkhead, then put a blanket on the floor with some toys (after take off of course!). Put your bag at the aisle side and it creates a mini play area – Priscille, mother of Rachael, 8 years, and Matthew, 6 years
When flying, I sometimes skip the early boarding call to allow more time for wiggles before we lock ourselves in a plane. Before you fly, also try to book a bulkhead or aisle seat to maintain access to the aisles without disturbing other passengers and giving kids the option to move around in-flight.
If your baby is still small enough to be worn in a carrier, wear them when you travel through an airport. Too often I’ve watched beautifully adorned fluffy pink car seats slammed face down onto the conveyor belt at airport security, soiled for eternity because TSA personnel cannot allow you carry the baby through the scanner in the seat. If you do decide to take the car seat with you, either for use in-flight or at your destination, purchase a bag for the seat to avoid getting it dirty. The same tip applies to strollers.
Road trips offer multiple chances to stop and get out and play with the kids and snack along the way. Allot 2-3 extra hours per 6 hour trip to stop for food, bathroom and play breaks. If your road trip is more than 8 hours, consider making an overnight stop.