I recently travelled to Mexico with my spouse, 8 year old and 6 month old! It has been a while since I navigated an airport with a baby, and have learned a few tips since the last time that I wanted to share.
Most airlines will allow a child under 2 to travel for free as long as they sit on the parents lap on the plane. If you take advantage of this, they do not get their own piece of free checked luggage however you are allowed to check two baby items (playpen, bouncer, car seat etc.) for free to the destination.
Some people chose to take a stroller which can also be checked with the baggage but I much prefer this to be gate checked (meaning you can take it right to the gate and it will be placed under the plane, and then you will get it immediately once you get off your plane in destination instead of at baggage claim). Now in this case I didn't use the stroller for the baby, I used it to hold extra stuff but as the child gets older and heavier, it comes in handy to carry them especially through an airport like Toronto Pearson where you seem to have to walk from one end to the other!
What I didn't do with my first child was babywear. I read somewhere before I left that if you wear your baby they do not make you take them out of the carrier going through security. Even though it makes it slightly hard to take your laptop, liquids and assist other children putting bags and their belongings on the belt to be scanned I must say overall it was SO much easier than having to take them in and out of a stroller.
My only mistake was leaving the soother clipped onto me as I went through the metal detector which of course set it off and I had to be scanned further.
Wearing the baby onto the plane also makes you handsfree to carry additional bags (that you no longer have the stroller to assist with) or help your other kids. It made the on and off process so smooth.
I did learn though on the way home that babies are not allowed to be in the carrier upon take off and landing as the flight attendants need to be able to take them from you quickly in case of emergency. So if you are babywearing, just make sure its an easy carrier to get them in and out of in the cramped airline seat, especially if they are sleeping and you don't want to disturb them!
The thing I went back and forth about before going was whether to bring my Boppy nursing pillow on the plane. Everything I read said don't do it, they are bulky and not needed. Personally my daughter loves sleeping, eating and hanging out on this pillow at home and so I couldn't see myself not bringing it. And I am sure glad I did! It made it more comfortable for her to sleep on my lap and when she was awake she could lay across it and look at the people going up and down the aisle. I could even prop it against the seat in front of me and have her lean on it to make it more comfortable for her to sit up (since that is the only way she wants to be these days)
The final tip is to make sure the baby is either eating or sucking on a soother during take off and landing. This is to help their ears to pop from the sucking motion and it worked great!
Overall, the process of travelling with infants should be fairly stress free! Our trip was a success and we hope to travel again soon!