Alberto E. Rodriguez/Getty Images; E! Networks Sweater dresses can be worn in many ways, making them a must-have for the chilly fall weather. A roomy knit minidress doubles as a comfy boyfriend sweater over jeans or leggings and can easily be dressed up with a belt and some killer heels.
Curvy girls like Jessica Simpson and Christina Hendricks who need structure in their clothing can get away with this look by wearing an all-in-one body shaper like this one from Spanx.
While someone petite like Nicole Richie can get away with chunky knits—they add volume—it's best to stick with a mid- to lightweight knit for the most flattering silhouette.
Vince is known for its amazing knits season after season and the brand has done the chicest sweater dresses for fall. Old Navy has also gotten in on the trend with this sleek boatneck dress.
And cinching the waist with an awesome corset belt (Azzedine Alaïa makes the absolute best ones) will create a sexy hourglass shape. Alaïa may not be attainable for all, but there are wonderful ones at every price point—from this luxurious Burberry belt to this one from MICHAEL Michael Kors.
Finally, don't forget about your tights! Darker colors are the most slimming (like these from Target), and stick to solids if your knit has too much texture or pattern. Also avoid horizontal stripes if you want your legs to look slimmer. And showing some skin is always sexy, so a sheer colored hose is a great alternative if you want something a little lighter than a tight.