Over the last year or so, Derek Lam really dug into his American sportswear roots, and he's seeing results. His business partner Jan-Hendrik Schlottmann reports that the ready-to-wear collection was up 30 percent last season over the previous one. The new lineup will prove equally popular at retail.

Lam has a knack for everyday glamour, and for Pre-Fall that starts with outerwear. A faux fur topper in woven taupe-colored mohair made a big statement; same went for a double-breasted coat in what looked like black pony hair, but turned out to be glossy silk velvet with a smart ribbed knit collar. Think you have plenty of trenches in your closet? Lam's dark denim version with matching jersey sleeves might have you reconsidering. A midnight blue cashgora toggle coat also looked like a keeper.

With its long, full trousers, crisp shirting, and suede platform loafers, the collection vaguely channeled Katharine Hepburn in her 1930s and forties prime. But it never smacked of retro. The designer's clean, unadorned silhouettes helped keep things modern. So did his experiments with volume and dimension. A sleeveless dress was cut in panels to create a vase-like shape below the waist; the fabric of another was manipulated so it almost looked quilted. It was an illusion—the dress was actually quite light. Fans will be happy to see a new take on his leather patchwork pieces; this season's pencil skirt was mixed with suede.