My friends are having a small wedding in August this summer, with a light 70s theme (she's wearing a long crochet dress, he's wearing a flared suit). The big ceremony is the day after, so the registry office do isn't going to be very formal.I'm at a total loss as to what to wear though We're all aiming for a retro, vintage look, without straying into the realms of fancy dress. I'm a curvy size 16 – 18, so I need something authentic looking, but that would also flatter an hourglass figure.I'd wear a cute, flowy tunic dress or eyelet dress. Try www.forever21.com, they have lots of casual dresses that still look great.