black mini cocktail party dress Womens Sequin Dresses Sleeveless Sexy V Neck Sparkly Prom A-Line Backless Short Homecoming Dress (Black, XS) : Clothing, Shoes & Jewelry Color:Midnight Shimmer Floral Tulle and sequins * Midi Evening Tommy Hilfiger Women's Sleeveless

black mini cocktail party dress Womens Sequin Dresses Sleeveless Sexy V Neck Sparkly Prom A-Line Backless Short Homecoming Dress (Black, XS) : Clothing, Shoes & Jewelry Color:Midnight Shimmer Floral Tulle and sequins * Midi Evening Tommy Hilfiger Women's Sleeveless

Tommy Hilfiger Women's Sleeveless Jewel Neck Colorblock Stripe Crepe A-Line Mini Dress, Ivory/Sky Captain/Ballerina Pink, 2 at Amazon Women's Clothing store

For a more formal look I’d consider black fishnet tights with a suede high-heeled simple court shoe

Midi Evening

Color:Midnight Shimmer Floral

It is always safer and more respectful to the host to opt for floor-length when formality is at its highest

Tulle and sequins * Fit Detail