If you’re one of the nearly 118 million Americans planning to catch a flight this summer, you may be looking to save money by packing light and not checking your luggage. Fitting everything you need into a carry-on bag is a great idea, but only if you do it the right way. If it’s too heavy, it could cost you money. If you have a banned item, it will be confiscated. SmarterTravel.com has seven key things travelers should do when packing a carry-on bag.

• Make sure it’s not too heavy and you can actually carry it and lift it up into the overhead bin.
• Be sure to check out the TSA rules pertaining liquids and the restrictions on any liquid over 3.4 ounces.
• Check the TSA rules about what other items are banned.
• There are very strict carry-on weight limits and if you don’t weight your bag before showing up at the gate, you could be charged to check the bag.
• If overhead space runs out before you get on the plane, you may have to gate-check the bag. If this happens, you want to make sure you’re not leaving anything in the bag that you might need during the flight.
• Many airlines allow you to carry on personal items like headphones, snacks, or a book, so don’t put them in your carry-on bag because it’ll take up more space. Put them in a small personal bag.
• Many budget airlines charge you for carry-on bags. Be sure to prepay for them because it will likely cost you more to do so at the airport.