I'm the one who took my 18 month old to India and he had so many lollipops he looked like he was shellaced, but it worked!
We actually didn't bring a stroller when we went since we knew it would be pointless to have at our destination. We did use a carrier, a Calyx, but any carrier would work. We also only had to change planes once and that was at the very beginning of the trip there, and very end of the trip back, since it was a direct 15 hour flight from JFK.
An extra outfit for everyone in the carry one plus at least one more for the toddler is always a good plan. If you don't have a huge problem with your child watching videos, we found our ipod priceless, it let DS watch, he didn't even want the headphone, just to watch the videos, and kept him quiet and happy.
I brought some window clings to play with on the airplane windows, since we had a window seat, some crayons and paper for drawing and stickers as well. I also brought some toy cars since DS likes cars. That being said, the ipod and lollipops are what kept him entertained the longest, and since he slept around two hours total on the flight there, we had to keep him entertained for quite awhile.
We also brought other snacks then lollipops, he had a bunch of freeze dried fruit which he enjoyed and he liked things like pretzels and such as well.
Looking back it wasn't as bad as we had anticipated, and it went by faster then expected, in the moment though we basically let DS do what he wanted to keep him calm and not annoy the other passengers on the plane.