I second this! I've actually had great success putting fragile prop items into one of those plastic storage bins (light, yet fairly sturdy) you can get a Walmart, packing small clothing items and/or bubble wrap around it in the bin, then putting the bin inside your suitcase and packing more around the bin. Also, you can straight up tell the airline agent taking your bag you have fragile items in it and they'll put some stickers on it for you. I'm not too sure if the baggage handlers actually heed those stickers, but worth a shot.