(1 of 7) Timeless Trend: TrenchesBesides the little black dress, there's no wardrobe item as indispensable as the trench. Favored by style icons of every generation, from Jackie O. to Janet Jackson, the polished-looking coat pulls together any outfit instantly. Versatile enough to pair with jeans or an evening gown, the tailored piece is favored by many of today's VIP fashionistas. To figure out how to wear yours--be it cropped, long, or in navy blue--take cues from these trench-loving trendsetters. Jessica Alba In an expert styling move, Jessica Alba layers a tailored trench over her billowing Lanvin gown for her appearance at Lanvin's Fall 2008 runway show in Paris. March, 2008.