What should you wear? A glamourous full skirted dress in an evening fabric will do. Here are pictures of several styles in brocade, chiffon, satin, and taffeta. Colors are clear and bright, black, white, or metallic brocades.
A skirt with a bit less flair, or a fitted sheath also works. A fitted dress should be jazzed up with lots of jewelry. 
Beaded sweaters or cropped jackets, sometimes with fur trim, can be worn over the dress if it is a cool evening. Swing coats and fur stoles are also appropriate.
Lots of sparkly rhinestone jewelry is appropriate, in necklaces, bracelets, brooches and earrings. 
Shoes should be spike or kitten heels with pointed toes. 
In makeup, go for a strong defined brow line, black eyeliner and heavy mascara, and a strong lip color. Hair is either pulled back tight to the head with a chignon, or teased high with a flip at the ends.
Most of all, have fun, and have a martini!
