Talk about la dolce vita: Twin-Set sells clothes fit for a stylish Milanese signora, the kind that spends mornings sipping espresso on a sunny terrace, the afternoon shopping on Via Monte Napoleone and the evening at La Scala. The luxe Italian line already sells its fineries to Holt’s, but this Yorkville outpost is the company’s first stand-alone shop in North America. Fabrics (silk, lace and cashmere blends) are meltingly soft; ribbons, sequins, beadwork and embroidery add dazzle to cardis, skirts and silk tanks; and there are items suitable for all stages of a principessa’s busy schedule. For luncheon, a cashmere cardigan in Valentine red; for a dinner date with a suitor, maybe a leopard-print skirt paired with a black sequined top. For a night of Puccini, a silk slip dress hemmed with lace. Prices range from $200 to $800.