I have flown with my DS since he was 5 weeks old.. So i have flow with a
5week old
6 month old
12 month old
18 month old
2 year old and then
2 children.. so a two year old and a 5 week old.. ALONE.

Its really not that hard at all...
INTERNATIONAL
-call the airline prior to travel to insure they know your child will want a meal
-Qantas has formula, organic baby food, spoons bottle, bibs, wips.. panadol, change of clothes of most size babies, toys, snacks, rusks etc
-Bring snacks with you lots of little things
-They will give you whatever water on the plane.. so dont bring water as large amounts they wont alwasy let you thought security.. TOTALLY DEPENDS.. who you get at security
-Qantas had stollers so you dont need to take your own unless you need it for baby to sleep in etc. or dont have one at the other end.

DOMESTIC
These are only max 6 hours so easy flights,
Snacks
New toys
WRAP the toys in wrapping paper for toddlers.. THEY THINK ITS EXCITING A NEW PRESENT!!
you can feed taking off or dummy.. neither of mine have ever had ear troubles and between them they are 8 months and 2 have been on 19 flights.. so they are fine.

MOST IMPORTANT.. RELAX>. its only a flight. big deal. ask for help.. Give the hosts your baby to hold while you are eating etc.. or even soemoen sitting next to you.. NO BIG DEAL.. people are willing to assist!
Dont pack the kitchen sink. as you need to carry a child/children and your bag!