How To Actually Dress Properly When The Invitation Says "Black Tie"

How to approach White Tie: This is as formal as dress codes get, so embrace it.
Ladies: Bring out your best full length ball gown and jewels. This is as formal as you're going to get with dress code. Long white gloves are optional, and décolletage or strapless acceptable.
Gentlemen: Black dress coat (tail coat) and matching trousers, wing-collared shirt with shirt studs and cufflinks, white piqué waistcoat and white bow tie, black patent-leather or calfskin evening pumps and black silk socks. (During formal daytime events, like Royal Ascot, morning dress is the equivalent attire for men; it includes a morning coat, waistcoat, tie, and striped trousers.)

How to approach Black Tie: "Always be mindful of your hosts' desires and anticipate what their vision is for their dinner, dance, fundraiser, wedding, whatever. What does black tie mean to your host—what does it look like to them? If it's Rihanna, well that's one thing, and if it's the Prince of Wales, it's another."—William Norwich
Ladies: A night for you to look your most gorgeous! Embrace it and have fun. Wear a long formal gown (if you have the opportunity to wear one, my attitude is why not?) or a shorter fancy cocktail dress that is black tie appropriate. Colors to keep in mind for winter: jewel tones, emerald, ruby, amethyst and, of course, black. Bring out your best jewels and high heels and jazz it up!
Gentlemen: There's really nothing as sophisticated as a man in classic black tie. He should wear a dinner jacket (also known as a tuxedo jacket) and matching trousers, bow tie, and cummerbund or waistcoast, and black patent-leather or calfskin pumps or laced oxfords.
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What to do? "Black tie optional? How cruel is that for men? Wear black tie and it’s likely you’ll look like the maître d but not the host. Wear a business suit and it’s possible someone will think you didn’t make an effort. And for women, it’s the risk of overdressing. Slits up the side of a long dress and get-down décolletage, proceed with caution. Dangling earrings shouldn’t droop lower than the jaw, or everything goes slack. "—William Norwich
Ladies: Same guidelines as black tie. Black tie optional is really geared more toward the gents.
Gentlemen: Dark suit (with a conservative tie and dark shoes) or a tuxedo if you're feeling particularly Bond-esque.
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"Keep it simple. Put the creative energy into your conversation not your interpretation of black tie. Besides, madcap patterns and colors might put you in competition with the décor. And the peonies and roses will always win."- William Norwich You can always err on the side of safety and dress in classic black tie, and if there's a theme, add an element like a conversational hat or accessory.

Pass on the parka: "By all means, wear a proper evening coat instead of a parka in cold weather although, but remember, there’s a certain status in 'no coat' because it says you left it in the car and kept the car (in cities where one ferries about with drivers) rather than arrived by bus or taxi."—William Norwich
Ladies: A fur or faux-fur shrug. A gorgeous velvet coat.
Gentlemen: Classic black or charcoal gray overcoat (ideally a Chesterfield style with velvet collar) and dapper scarf will do. Sadly, your down jacket, regardless of how cold is it outside, just does not fit the occasion.

Ladies: Many of above recommendations still apply but women should feel free to mix in pastel hues, especially for summer weddings.
Gentlemen: White dinner jackets made their debut in the 1930s as "a way for well-heeled vacationers to dress formally in the tropical heat without having to endure the heavy and dark-colored fabrics that were standard for evening wear at the time," blacktieguide.com reports. In America, the light jacket is now appropriate to wear during the summer months, especially at weddings and formal occasions in the country.
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