4. A Reusable Water Bottle

Regular travelers would have realized that airports have become extremely strict regarding what you can and can’t carry onto a plane. This has come about thanks to the modern day issue of terrorist attacks, which has unfortunately resulted in a ban on water bottles with more than 100ml of liquid in them. This makes an empty reusable water bottle a must, as water sold at airports is generally extremely expensive. For most travelers however, a reusable water bottle is regrettably one of the most useful but common things we forget to pack.