When packing your carry-on, What Not to Pack in Your Carry On Bag? Leave behind liquids over 3.4 ounces, sharp objects like scissors or knives, flammable items such as lighters or aerosols, and firearms or ammunition. Avoid packing perishable foods, as they may spoil during your flight. Remember to double-check airline regulations to ensure a hassle-free journey. Keep your essentials handy and your travel smooth.