Ours travelled remarkably well with Singapore airlines...gotta love those computer screens.
I took pyjamas and a change of clothes...5-6 small new toys and games...
I ask for extra blankets/pillows, and we are a family of 5 and we seat one adult with one child, and one adult with two children - and we move around - the only time the kids have to be in their allocated seat is for take off and landing.
Ask for extra snacks if needed.
Ask for help if needed.
Don't be afraid to walk around the plane, but not when the 'seatbelt' sign is showing...also, make a habit of taking the kids regularly to the toilet because they have to hold on if the 'seatbelt' sign is on!
Take and extra change of clothes for yourself too - two of ours vomited on the plane and it's not fun if you also get it on your clothes
We took the A380 connection leaving Zurich - we got out of bed fairly early, went to the airport, the flight didn't leave until I think 11am, we adjusted one watch for Sydney time, the plane was running on Singapore time, and we left one watch on Zurich time.
The staff will serve meals according to the destination time, which won't coincide with the kids normal eating - so ask for meals to be served for the kids at a specific time.
If you have dietary needs, make sure they are booked with your ticket, and alert the staff...
My general advice is always 'plan for the worst and be pleasantly surprised when it isn't quite that bad'...
I did change the children into their pyjamas for 'bedtime' and enforce a screen ban! - once the computer games were off they actually went to sleep really easily with the motion and sound of the airplane..
I never recommend sedatives/medication for children - I don't like being 'out of my head' so I can't imagine children would like it either - and I certainly have been on flights with medicated children who vomited a lot!