1) patience
2) patience
3) patience
4) small bottle of vodka
lol, seriously, it isn't fun with a young one, but it is doable and may not be as bad as you expect.
when i took my two to canada a few months ago, i was VERY well prepared/
1) each child got a small insulated bag of snacks. raisins, rice crackers, indiv. wrapped cheese, a couple of sucking candies, and a couple of bite-sized chocolates, and an apple.
2) each child had their own backpack that they could pull themselves, and did! inside each bag, there were 3 toys that they chose themselves, their "little blanket", and a small pillow. also, there was an A4 sized zip bag that i prepared ahead of time, they knew there were surprises, but they didn't know what was in the bag. in each bag, i put a notebook, a small pack of crayons, 10 sheets of stickers, 5 ink stamps, a small water colour paint and brush, a reading book and some foam stickers. I also packed their homework from school, so they could do some on the plane.
3) each child had a small hand-held "tv" that i loaded their own movies/tv shows onto. they also had their own headphones.
4) in my carry on bag, i had a change of clothes for each of the kids as well as for myself. i also had their pyjamas, so that they changed into them on the plane.
5) i also packed a new toy (still in packaging) for each child. they were allowed to open them just before we boarded (so we could throw the packaging away before boarding.)
we flew through BJ and had a 2 hour stop over there. there is a small area in the airport that has a playground and my kids were able to run around and play between flights.
all of this might not apply to you, but i found it to be a great time and not so difficult... i actually found it much more stressful when daddy came back to hk with us... i wasn't as well prepared, and i felt it.
only other advice? do NOT fly china eastern or air china!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!