Some tips:

Remove the handlebars -- they'll still be attached by the wiring by you can move them around to fit.

Remove wheels -- flatten tires, and you might want to remove the skewers too.

Remove pedals -- place them in a bag with the skewers and either tape them to the bicycle or put them in another piece of luggage (not your carry-on)

Remove seatpost with saddle on top -- BUT mark the seatpost before you remove it so you know the height of your saddle.

And if you've got racks and fenders you may need to remove them as well.

If you've got ANYTHING carbon on your bicycle, wrap it well.