I have never taken off my front disk, but my front wheel is securely zip tied to my frame as in the photo, and the black plastic disk protector is securely held in place with tape.

As mentioned, even with mechanical brakes as I have, you want to insert some sort of spacer, clean folded paper, whatever inbetween the pads, and held in with tape, so that when, not if, the front brake lever is squeezed by accident, the pads are not pushed out past where they should be.
If you have hydros as mentioned, you have to very careful of this.
Read up on hydros and this occurance to find out the pitfalls.

bottom line, pack your bike like a new bike is packed when delivered from the factory. You do not want any movement in the box, or as little as possible, use foam bits and the 3 most important plastic pieces to protect fork dropout, rear derailleur and front disk.
I have mostly used panniers and can carry these three pieces with me if I need to get a new box for a return flight.

if you ask politely at a bike store and be there for their unboxing day, they will save all the foam and plastic protector bits along with the used box.
check out the other thread on "bag vs box" if you want more info, I'll add the same photos I did on that thread.