old navy navy blue dress Women's The Occasion Fit & Flare Taffeta Mini - 95% Rayon 5% Spandex Length Old Money Knitted Dress Navy

The back of this lace gown is completely open, while illusion tulle gives the effect of floating buttons

Up until that point, Dianas style had been all pale pink and baby blue netting and sequins, she told British Vogue last year, and said that the black, strapless gown was Diana's first grown-up dress

Long Sleeve Winter Formal Dresses Free shipping on long sleeve winter formal dresses at GemGrace.com

Wear it knotted at the waist rather than tucked in just tie the bottom two sections into a loose knot to create a relaxed cropped effect that defines the waist while keeping the proportions easy

No-go: Tuxedos (too formal), overly casual suits (e.g., linen)