For Men
Tuxedos should be paired with a starched and pleated shirt. White or black bow ties are appropriate, depending on the dress code.
Dark suits with conservative button-down shirts and ties are acceptable for formal events not specified as white tie or black tie.
Well-cared-for leather shoes pair well with formal outfits. Wear patent leather shoes with a tuxedo.
Feminine Styles
Floor-length evening gowns should feature a dressy fabric, such as taffeta or satin. Choose dark colored evening gowns in hues of black, navy and gray for evening affairs. Daytime events during warm months call for lightweight but luxurious fabrics such as silk chiffon or silk crepe.
Knee-length cocktail dresses or the classic little black dress are also appropriate for formal occasions. For black tie optional events, dressy separates are another choice -- for example, women can pair a silk blouse with well-tailored pants and a pair of pumps.