Whenever I fall in love with a fancy frock that is categorized as "evening wear" I always finds ways to wear it for casual occasions using a few tricks of transformation.  Cocktail dresses need not be confined to formal events.  Always remember that rules, especially rules regarding fashion are only silly social constructions and ultimately, are meant to be broken.  I found this gorgeous lace, scalloped hem gown at Stella Dallas, one of my favorite vintage stores.  I had it hemmed to knee-length and I wear it for both formal events and casual encounters.    When converting this lace dress into a daytime look, I pair it with structured pieces that contrast with its delicate femininity.  My favorite "casualizing" accents are chunky, textured sweaters, sheer white shirts, blazers, dark tights, big structured bags, and boots.    

Dress: vintage (Stella Dallas)
Blouse: American Apparel
Purse: Vintage Ferragamo
Shoes: Gap
Bangles: Assorted