This week we highlight fall suiting, the perennial cool weather staple reinvented for 2012, rolling numerous trends into one form-fitting package. Notably, in a striking return to the dark side, we see through several designers’ interpretations that black is the new black.  Also, leather trimming and waist-cinching smoking jackets will make a big impact moving forward.   The trickle-down effect in the suiting segment, from couture and ready-to-wear to fast fashion, will be huge in the retail market place this coming season. Look for everyone to knock off these items in pleather and lighter fabrics. In fact, we’ve already spotted iterations on the selling floor at JCP.   Below, we present our top picks in suiting separates from the fall collections.       Yves Saint Laurent debuted the original Le Smoking tuxedo suit for women in 1966. For Fall 2012, YSL (or Saint Laurent Paris, as you wish) Creative Director Hedi Slimane’s leather-collar blazer is our top pick.                     From 3.1 Phillip Lim, a collar pops in patent.                         Trimming before his time, Alexander Wang also knows that the shoulders are the last to go.                       Rachel Zoe’s entire collection, was ‘70s chic. Here, a slim-fitting leather suit swaps slacks for shorts.                       Finally, Christopher Kane trimmed in leather throughout his entire collection. YSL would be proud.                     (Photo credits, from top: 1. NeimanMarcus.com, 2. Monica Feudi/Feudiguaineri.com via Style.com, 3. Monica Feudi/Feudiguaineri.com via Style.com, 4. Filippo Fior/GoRunway.com, 5. Gianni Pucci/GoRunway.com)