If you've ever noticed a flight attendant giving you some serious side eye, it's probably because you packed one of their no-go items. You know, like a "carry-on" that's not quite carry-on size, or odorous food like salmon or broccoli the whole plane can smell. Hopefully, you're well aware of what not to wear on a plane. Still, there are plenty of other things that flight attendants, and travel writers like myself, have learned over the years not to bother bringing on board.