If you can afford a 6k $ bike, buy a proper travel bag.
- Helmet, backpack and small things
All my stuff I need for the trip are in the bike bag. I put the clothes around the frame for protection. The backpack is also used for some protection. Try to put the heavy stuff at the bottom of the case, for some stability. Be sure nothing is moving around and everything is fixed properly. In case the bag's zippers are failing, the content of the bag will not go all over the place.
- Book your bike into the flight
Notify the flight company that you are travelling with your bike. Let them know about it in advance, in many cases you have to pay extra for the bike. Very important, don't forget to specify the size and the weight of the bag. Give them a heads-up, you would like to get your bike at the arrivals in the same time with you. Waiting for a few days to get your bike could ruin for good your trip.
- Be early in the airport
If you are travelling with your bike, the two hours rule doesn't apply to you.
It will take time to move around, to find airport carriages (sometimes you have to pay for it), and after you check in, you will have to take the bike to oversize baggage on the other side of the airport and go again to the check-in and claim your ticket. And yes, and a short visit to the airline company office to pay for the bike.
- Transfer from/to airport
Another thing that I learned on the hard way, if you book a transfer from/to airport, notify the transfer company that you are travelling with big bag.
Book the transfer in advance, calling a taxi two hours prior your flight it's a very bad idea.
Bike bags don't fit well in small cars. Or just ask for a van.
- Be nice with the check-in staff
No matter what is the airport policy regarding bikes, the check-in staff will decide how this policy is applied. Just be nice, no point getting angry with the check-in staff.
Don't fight with them, if they made an error and they overcharged you for the bike call the info-line and you will get a refund later.
- Insurance insurance insurance
Buy insurance for your bike, just in case, you never know. In most cases it will not cover the value of your bike, but anything is better than nothing, right?
I'm flying everywhere with my bike for a few years already, and so far my bike have survived, in part because in some extend the airport baggage handlers do care, in part that I take care when I pack the bikes in the bags.
There are marks of abuse on the bags, they are scratched badly, a small hole in the EVA Pod, but and the end as long the bike is protected, the bike bag did it's job :)
Pack the bike properly, and your trip will be fun.
P.S: don't forget your axles home ;)