NEW YORK --- The most important thing to do before incorporating a wide, waist-cinching belt into your fall wardrobe is to take a good look in the mirror, say fashion experts.

"While (the belts) accentuate the waist, they can also accentuate figure flaws," says Gregg Andrews, a fashion director at Nordstrom. "You need to look head to toe."

The wrong belt could emphasize full hips or a wide backside, he says, adding that a narrow one, though less trendy, might be a wiser choice in the long run.

Clinton Kelly, co-host of TLC's What Not To Wear , focuses on placement on the torso. He describes a belt as "an arrow" that directs attention to one place -- so you want it to be somewhere you want noticed.

With the belts forecast to be a hit this fall, here's a primer on what and how to wear them:

- The width should be proportional to your height. Taller women -- think first lady Michelle Obama -- can wear a wide belt, but it's not for the petite woman. It would take up too much torso, he says, creating a choppy silhouette.

- Borrowing again from Mrs. Obama, the belted cardigan will be big for fall. "We're going to see cardigans in every length from the hip bone to the midcalf length, and adding a belt to a cardigan is a new way," Mr. Andrews says.

- Shop your closet with the wide belt, suggests Suze Yalof Schwartz, executive fashion editor at large for Glamour . "The wide belt can make every piece in your closet feel new."

Dresses, button-down shirts, a boyfriend jacket or a blazer are all potential partners for the belt, she says. The only items to stay away from: a thick sweater or shrunken jacket.

- Belts can be worn with casual, work and evening clothing.

- The top of the belt should hit at about the middle of your ribcage. "When it's higher than that, it starts to manipulate the proportions," Mr. Andrews says.

But Mr. Kelly has a caveat: If you have a thicker waistline, move the belt up a little higher to create an almost empire-waist effect. That will draw attention to what is likely the narrowest part of the body and create a longer, leaner leg-line.

- Popular fall belt colors include black, gray and brown, but this autumn is all about texture. There are aggressive belts outfitted with studs, nailheads and grommets, and more subtle and sophisticated choices made from an exotic skin or suede.

- While wearing a wide belt, don't overdo jewelry. Oversize earrings could work but watch out for necklaces so long they come near the belt.