Photo: Alex Beauchesne

A: There's nothing more modern for night than mixing everyday and dressy pieces, like a regular sweater (dual-function items save money) over a long, festive skirt. Or work the masculine-feminine duality of the tuxedo, which is very popular this fall (the late, great Yves Saint Laurent pioneered the women's version). Always smart: casual basics in fancy fabrics (charmeuse, lace, metallics) that give you the comfort of a tee, tank, or drawstring pant while still looking party-ready.


The new reliables: 
From top: Turtleneck: Ralph Lauren Black Label, $525; Ball skirt: CH Carolina Herrera, $780; Sparkly belt: Ann Taylor, $36

Tuxedo jacket: BCBG Max Azria, $318; and shirt: Kate Hill; $68; dressed down with jeans: Fidelity Denim, $188

Sequined tee: Cardigan: $695; and silk skirt: CH Carolina Herrera, $430