I think you definately need a good carrier - maybe like an ergo? even a baby bjorn. Maybe check ebay? I think its a MUST for travelling.
Ive done heaps of trips with my girls to Melb and Perth.
Are you b-fing? B-fing was wonderful on my trips!
Also I like to stick to their normal bedtime routines if I can - if going on an evening flight I would do dinner & bath & jammies before the airport.
I don't know what else I can recommend?
All the best though