BLACK
Yes, tuxedos are black, and you'll almost certainly see an abundance of dark sport coats at any union, but black is traditionally a no-go color at weddings -- especially for women.
Black dresses connote mourning and death for many people, but there's a difference between showing up to your best friend's nuptials in funeral garb and wearing a sleek, little black number to an evening wedding. As long as the dress feels fun and light, regardless of how dark it is, you should be fine. Sequins usually work, as do black cocktail dresses for formal ceremonies. However, if there's even the slightest chance it could fit into a procession for the deceased, put it back on the rack and slip into something more colorful.
A SKIMPY OUTFIT
Nothing screams "look at me" like a skimpy outfit.
There's nothing wrong with showing off a little leg or décolleté every once in a while, but there's a time and place for such things, and weddings aren't one of them.
No, you're not exactly showing up the bride, but showing off your assets is a surefire way to take away from her big day, so don't do it.
JEANS AND A T-SHIRT
We don't care how casual the wedding is and how laid-back the bride in question might be, attending in jeans and a T-shirt is not an option.
It doesn't matter if it's on the beach, in your mom's backyard, or even if you don't know the couple very well. If you're bothering to show up, the least you can do is throw on a dress or a pair of khakis and a button-up shirt -- again, assuming it's a casual ceremony. Also, just to be clear, don't even think about slipping on a pair of flip-flops. Pumps, heels, flats, loafers and sandals are a go, but plastic footwear is a huge wedding no-no. (Possible exception: If the wedding invite explicitly states that it's a "flip-flop casual" beach event, you may wear them.)
A TUX
There's only one guy in a penguin suit here today, and it's not you (unless, of course, the ceremony is a black-tie affair, in which case you, the groom, and every other male in attendance is bowtied out).
However, just as it's in bad taste to upstage the bride, you shouldn't go out of your way to one-up the groom. Although it's doubtful he'll run into a closet and weep or complain about you to all his friends if you show up looking better than he does, it's just not polite. Yes, we know you can't do anything to tone down your innate good looks, but the least you can do is dress them down in a sport coat and leave the super-suit to the man saying "I do."
A PANT SUIT
You're going to a wedding, not a meeting at the office!
Drop the business persona and show your style in a skirt, dress or any kind of clothing that would look out of place with a coffee stain. This is a celebration of two people choosing to unite their lives together forever, so the least you can do is find something that isn't overly stuffy and businessy to wear. We're not just talking about your standard black or charcoal suit. This rule also applies to pretty pastel skirt-jacket combos. They might work for a dinner event, but they just set the wrong tone for weddings.
ANYTHING MISTAKEN FOR A WEDDING DRESS
It's never a good idea to wear anything that could conceivably be mistaken for a wedding dress. But, just like the tradition against wearing black to on the big day, we think this rule can be broken -- if you go about it the right way.
A simple, off-white dress or skirt should be fine, and if you want to be absolutely sure you're not stepping on any perfectly manicured toes, get a glimpse of the bride's dress before the big day. Make sure your white outfit of choice is dramatically different, so if she's wearing a full-skirted gown, your slender, white evening gown shouldn't pose much of a problem. If she's wearing a simple number, though, pick another color. Even if you look your best in white, you won't care what color you're wearing when she's staring daggers into your eyes instead of saying "I do."
