We have been really blessed to be able to travel to Hong Kong quite a bit this year. Most flights were taken with the Daddy but after paying exorbitant prices for a short 4-hour flight, I decided to heck it and go for the budget option which was slightly more than half price. Brave, i know.
So here's what worked for me when flying with my little one.
1) Choose a flight where your child will spend the most time asleep.
The flight there was a breeze. The front row seats for Jetstar Asia were reserved for passengers who paid more, but they reserved the second row for passengers traveling with infants. Good enough for me! Because we chose a super early flight (6.30am), Shanah slept through most of the flight, waking only to nurse. Success!
2) Bring along a few of your child's favourite snacks
The flight back was a challenge - it was right smack in the afternoon and Shanah managed a 1.5 hour nap. When she woke and fussed, i took out some grapes (her favorite then), which kept her occupied for quite a bit. When she grew restless from sitting on my lap, I placed her on the minute space between my seat and the seat in front while she picked on more grapes. When the grapes lost their attraction, i began rummaging for crackers, which quickly lost their powers due to the law of diminishing marginal returns.
3) Prepare a flight bag of activities (books, toys, etc)
Shanah gets a new book each time we fly because a new book always appeal to her for the longest time. Sometimes I buy them ahead and keep them for the flight while other times i simply bring along an old favourite that she hasn't read for awhile.
We also downloaded some kids app on the iPad as a last resort. I like the idea of the iPad as a special treat so that we can use it to bribe and cajole a screaming baby. Unfortunately when this baby wants to scream, she simply screams.
4) Always have the ultimate bribe prepared
The ultimate plane survival was... Ben & Jerry's ice cream! Thank you Jetstar for carrying that!! I don't know any toddler who can resist ice-cream, especially when allowed to feed themselves with spoon, hands, fingers and toes. :) I didn't hadve the hands or energy to capture good photos, so here's one with a really happy girl and her ice cream.
5) When all fails, grit your teeth and give the little one loads of cuddles and kisses
It's tough being little and kept in a confined space :)

Well, there are actually a bunch of other practical stuff that i always carry along - like my usual baby bag, TONNES of wet & dry tissue, water, gummies (in case the ears get blocked due to air pressure) and a toy or two. I heard of some people who feed their babies cough medication to get them to sleep - though i have my reservations about this.
If you are looking for more advice, hop over here - not the best, but pretty sound!
P.s. If you are flying for the first time, one of the main concern would be your baby handling the change in air pressure during ascend and descent. Allowing them to suckle or drink fluids will help them handle it better.