What every girl needs: the perfect formal dress by smileitmakespeoplenervous featuring evening dressesMichael Kors purple mini dress / Preen blue dress / Vivienne Westwood Anglomania knee length party dress, $855 / AFTERSHOCK deep v neck cocktail dress, $365 / Coast evening dress, $81 / Yumi white skater dress, $66 / Prom dress / Jeane Blush red sequin dress, $53