It's no fun to pack your favorite snack or shampoo in your carry-on bag and learn that it doesn't meet TSA regulations and you'll have to leave it at security. Here is a big-picture guide to airline baggage and airport security regulations to help you pack like a pro and breeze through security on your next big trip. Since regulations frequently change, make it a point to check for the most updated information with your airline and the Transportation Security Administration | Transportation Security Administration (tsa.gov) a few days before departure.

Travel advisors and frequent flyers know the 3-1-1 rule, a rough formula for airline carry-on baggage established by TSA that mandates that you can only carry liquids, aerosols and gels in 3.4-ounce containers, which must be stowed in a one-quart, plastic zip-lock bag; one per passenger. The rule applies to common items such as toothpaste, shampoo and food and extends to wrapped gifts or packaged collections including lotions, creams, scented oils, liquid soaps, perfumes and even snow globes.

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While you can bring, nail clippers, safety razors and travel-sized or blunt scissors in your carry-on baggage, you'll need to pack larger tools such as a hammer, drill, pliers, etc in your checked bags. Wrap any sharp objects in your checked suitcase so they don't damage your bag or injure baggage handlers or transportation security officers.

To prevent unintentional short-circuiting and fires, there are rules about lithium batteries, commonly used in digital cameras, cell phones and laptop computers. For checked airline baggage, batteries must be installed in the electronic devices. In carry-on baggage, you are limited to 8 grams (100-watt hours) of lithium batteries and they must be in original packaging or a protective case. The transportation security officer at the airport may deem some items too dangerous to permit through the checkpoint. Check with TSA in advance if you're unsure about prohibited items.

Crowded planes are making airlines stricter about carry-on luggage. Check with your travel advisor or airline about the maximum size of carry-on baggage and save yourself from extra hassles by checking bags that are larger. It's always helpful to pack light and organize the contents in all your bags so everything can be easily seen at a glance; otherwise, it can all spill out if an airport security officer needs to look inside. Traveling light can also help you avoid added baggage fees for overweight checked luggage.