By Ashley M. Heher, AP Retail Writer

CHICAGO (AP) — Carrying your bag onto the plane yourself means you'll skip more than just the airport's baggage claim these days.

Traveling with a suitcase that will fit in the overhead bin can save you more than $25 in bag-check fees that most airlines now charge. So it has become essential to master the tedious task of cramming all your necessities — and that third pair of sandals — into a small suitcase.

Here are five ways to ensure you fill your suitcase wisely — and can zip it closed on the first try.

MAKE A LIST: Then check it twice. Once you know what activities you have planned — what type of weather is forecast — place everything on your bed. Then put half back.

"People overpack all the time," says Julee Wilson, staff fashion editor Real Simple magazine. "We always think we need more than we do. But you can definitely pack everything in a carry on."

BE UTILITARIAN: Look for clothing that can pull double duty. Susan Foster, author of "Smart Packing For Today's Traveler," says being choosy about what she puts in her suitcase lets her travel with just a 22-inch carry-on — even for a recent three-week trip to Europe.

Regardless of gender, she recommends travelers pack two pairs of slacks, four tops, a jacket, a sweater and no more than three pairs of shoes, including a sturdy pair for walking and a pair that matches both dressy and casual clothes. Then she adds pajamas and sundries.

"The only difference between a week and a month is called laundry," she said. "You just wear the same things over and over and over."

Foster also recommends taking extra care in choosing fabrics and colors. Opt for items that can be layered for warmth or mixed and matched to add a splash of color. She's even meticulous about small things like underwear.

"Pack three pairs of underwear for a trip of any length. One to wear, one to wash and a spare," she said.

To make sure items dry quickly, she takes quick-drying fabrics that can air dry overnight in a hotel.

KEEP TOILETRIES TINY: Toiletries can account for one-third of the weight of an average carry-on, so paring back here can create enough room for another pair of shoes or even a complete outfit. While many grocery stores and pharmacies offer some travel-sized products that meet the FAA's 3-ounce limit for liquids and gels, frequent travelers may want to check out, which sells more than 2,000 travel-sized items from organic shampoo to games.

LAYER CAREFULLY: It's not just what you pack, but how you fit it in your bag. If you're using a wheeled suitcase, put heavy items like shoes at the base by the wheels and work your way up to balance the bag so it doesn't tip over. Figure out what you'll need when you arrive at your destination and layer that on top.

In between, instead of folding, roll knits and denim so they take up less space. Save the folding for easily wrinkled items like dress shirts and blazers and place those on top of the rolled clothing.

For extra precaution, put a dry-cleaning bag on each layer of clothing so items can move without building up wrinkle-causing static.

FILL EVERY NOOK: Between the layers of larger items, look for holes and pockets and plug them with small items like scarves or socks.

Wilson recommends putting jewelry in old film canisters or pill cases that can easily be shoved into crannies. Even the molded cups of a bra can store smaller things. And shoes make perfect temporary containers.

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