Each item must be 3.4 ounces or less and must be able to fit inside a one-quart size clear zip-top bag. The limit is one bag per person. Typically, travelers put their toiletries in the bag such as shampoo, hair products, make-up and toothpaste.

To pack a TSA-compliant clear bag effectively, you must strictly adhere to the "3-1-1" rule: liquids, aerosols, gels, creams, and pastes must be in containers of 3.4 ounces (100ml) or less. These containers must all fit into a single, quart-sized, clear plastic, zip-top bag. To maximize space, it is best to use travel-sized bottles that are rectangular or flat rather than round, as they stack more efficiently. Place heavier items like shampoo and conditioner at the bottom and smaller items like lip balm or travel-sized toothpaste in the gaps. Avoid overstuffing the bag; if the zipper cannot close easily, you risk the bag being rejected at the security checkpoint. It is also helpful to consolidate multi-use products, such as an all-in-one soap/shampoo, to reduce the number of bottles. Keep this clear bag in an easily accessible pocket of your carry-on or at the very top, as you will need to remove it and place it in a bin for X-ray screening unless you have TSA PreCheck.