Cardigans are big for fall 2009, but what's the strategy for making a cardi work for you? The key is to choose a shape that works with your figure, and then style it in a way that flatters your wardrobe.

Cardigans never really go out of style, and in a season where they're trending, your options are almost limitless; you can find great cardigan options in all shapes and sizes, at every price point. But how do you know what cardi is best for you?

A long belted cardigan is super versatile; wear it with jeans for a casual Saturday or with a pencil skirt for the office. A belted cardi will define your waist and give even the most casual look a pulled-together edge. If you're curvy or have short legs, look for a cardi that hits just at the widest part of your hips, not below; if you're slim or have long legs, opt for a longer cardi.

Pair your belted cardi with jeans or a slim skirt, or -- if you're comfortable -- with leggings. But remember: Leggings are a yoga pants alternative, not work wear. Save that look for the weekend.

A belted cardigan is a nice way to define your waist, no matter what your size or shape. Tie the belt at your natural waist, even if that is slightly higher than the waistband of your pants; For a little extra pop of color or texture, change out the belt that came with the cardi; just be sure to choose a belt that is proportionally appropriate for the sweater (a chunky sweater needs a fairly substantial belt, for example).

Pictured:Old Navy cable-knit tie-front cardigan, $36.50. Available in four colors in sizes XS to XXL.

For a sleeker, more classic look, opt for a slim cardigan in a lightweight wool or cotton. Look for one with really beautiful buttons for an easy upgrade -- but don't save the fancy cardi for work; pair it with jeans or cords for the weekend, too.

Layer your slim cardi over a blouse with a ruffled front; belt it over a dress or skirt. A slim cardi should hit at the high hip for the most flattering fit.

Ann Taylor merino crew neck cardigan, $80. Available in seven colors in sizes XXS to XXL.

The cardigan is a great staple for your closet; it's easy to dress up and can take other pieces from office to weekend and from day to night. Layer a cardigan over a strapless dress for cool weather, or for the office; replace your suit jacket with a belted cardigan for an updated work look. Pair an embellished cardi with boyfriend jeans for a night out. Embellish an existing cardigan by changing the buttons or adding a pin (or three).

Michelle at College Fashion dresses a fancy party frock down for dinner with the family -- by adding a cardigan!

Corporette reminds us that a patterned cardi is a nice alternative to a jacket -- what's your take on this plaid cardi? I love it.

And Stylemanship has cardigan suggestions for the guys (complete with visuals).

Susan Wagner writes about pragmatic fashion at The Working Closet and chic suburban living at Friday Playdate.