Wedding Guest Dresses Elegant Black Tie, Formal, and Cocktail Styles The Perfect Black Tie Wedding Guest Dress: 9 Gorgeous Gowns Bergdorf Goodman Amazon.com: Adrianna Papell Women's Sequin Embroidery Dress, Almondine, 4 : Clothing, Shoes & Jewelry Which dress for a "Formal" attire wedding. Been to many black tie optional weddings but never "formal". Wedding is tomorrow in the Midwest. : r Weddingattireapproval Your dress code: Garden Party Formal. Your guests: Absolutely serving. I love a classic black tie wedding but something about garden party just speaks to me!!