Water Bottle
The prices that airports charge for a bottle of water are embarrassing, and when I can, I try my best to be environmentally responsible. Thus, an empty water bottle is part of my kit any time I’ll be flying. Here, being empty is the important part, as you’ll have to dump it out before going through the security checkpoint anyway and that’s one extra thing you don’t want to have to make time for if you’re already on a tight schedule.