* Be reasonable about the amount of carry-on luggage that you bring. FAA rules require airlines to limit the amount of carry-on baggage, and if you try to carry too much with you, the crew may insist that you check in some items. (There is no universal limit; it depends on the aircraft type and the passenger load.) A bag that is not properly stowed could turn into an unguided missile in an accident or block the aisles during an evacuation. Check for size and weight restrictions before you go.
* Be careful about what you put into the storage bins over your seat. The overhead compartment doors may pop open during an accident or even a hard landing, spilling their contents. Also, passengers in aisle seats have been injured by heavy items falling out of these compartments when people are stowing or retrieving belongings at the beginning or end of a flight. Please be considerate of others and put hard, heavy items under the seat in front of you; save the overhead bins for coats, hats, and small, soft bags.
* As soon as you sit down, fasten and unfasten your seat belt a couple of times. Watch how it works. There are several kinds of belts, and in an emergency you don’t want to waste time fumbling with the buckle.