Age-Wise Style: Why a Coatdress Is a Must-Have

InStyle’s Fashion Director Cindy Weber Cleary has been a fashion editor for the past 20+ years. Needless to say, she's picked up some tricks along the way. Catch her column here each week for how-to tips and style secrets on her favorite, timeless styles.

Not every trend of the season has me rejoicing (Overalls? No, thank you.), but there is one that is worthy of an investment: the coatdress.

I have always loved shopping and appreciated tailoring. When I was about 11, I selected a grey-and-white-houndstooth-check wool coatdress to wear to my grandparent's 50th anniversary party. My female cousins wore pastel party dresses with crinolines, but I knew my dress when I saw it.

In the '80s, when I started my fashion career, one of my favorite purchases was a black gabardine double-breasted coatdress with a peak-lapel by the late designer, Willi Smith. I wore it constantly—with a crisp white shirt underneath for work, with nothing underneath for evening. Fast forward almost 30 years: This white cotton and linen gabardine trench from Michael Kors (above) works double-duty as a dress or a coat.

5 Reasons to Love a Coatdress

1. The hourglass shape is womanly but not restrictive.

2. The neckline shows a little skin but isn't too low.

3. The length hits at the most slender part of a woman's leg.

4. The defined shoulder isn't too exaggerated, but gives just enough line to boost your posture and slim your figure.

5. Clean lines and elegant accessories are always "in style."

Get the look:Topshop coat, $158, topshop.com.Michael Kors belt, $395, michaelkors.com.Zara bag, $100, zara.com.Vita Fede earrings, $300, shopbop.com.Derek Lam shoes, $625, shopbop.com.