Hi J., my family lives in Austin, TX and we live in Portland, OR, so we've been flying back and forth about two or three times a year.
My suggestion is 1) have your child drink something during take off and landing, this will help their ears. 2) lots of "snacks", special snacks that they don't usually get, my daughter eats very healthy, so a few hour flight with "perks" I feel is totally worth it 3) we also bought a portable DVD player, my daughter loves baby einstein videos...that was HUGE, you can turn the sound down really low, and the people around you will appreciate it too. 4) and last, but not least, a special new toy or something, something your child hasn't seen yet...this will be a little easier when the get older, but you know what makes your child tick!
Good luck to you, and remember, just have a lot of patience. You can do all that you can do. If your child does "freak out", just shrug your sholders, give a gentle smile and "sorry" to those around you. You'd be surprised at how sympathetic people can be towards someone traveling with a small child.