New York is awash in French brands of late (Céline, Carven, Sandro), but designer Juliette Longuet—who launched her eponymous label in 2003 and whose first-ever store (153 E. 70th St., nr. Lexington Ave.; 917-518-6557) opens on September 13—is one of few designers who offer personalized advice to clients. “I want to give them styling tips,” says the Reims-born, F.I.T.-educated Longuet, whose two-story, 1,500-square-foot boutique and studio are located in an Upper East Side townhouse. Longuet tapped architect Guillermo Gomez to consult on the design, which feels “very Parisian, very Haussmannian,” with high ceilings, chandeliers, and a fireplace. The collection infuses form-fitting Parisian cuts with a dressy New York edge and includes on-trend pieces like leather leggings ($995) and a rabbit-fur vest ($750). Fabrics are sourced from France and Italy, but the collection is made in the garment district, proving Longuet knows how to blend the best of both worlds.