A wedding is a celebration, and your clothes should reflect that. The pictures of that day are going to be in the bride's and groom's lives forever, and beautifully dressed guests really help set the mood.

· Dress up. Being underdressed is the worst feeling, so I'd rather overdo it. Even if an invitation says "casual attire," the furthest you should take that is a floaty cocktail dress or simple sheath. For a black-tie wedding, a long, formal dress is always appropriate, but if you'd rather go short, choose something knee-length in an opulent fabric. Silk charmeuse has a glamorous, '30s vibe and looks effortless but still fancy.

· Take a hint. The location of the event is a big clue about what to wear. If the wedding is on a beach in Mexico, it's pretty obvious that you should stay away from heavy beading. I love chiffon for a resort wedding. It's romantic, dreamy, and elegant. If the party is in a more traditional setting, like a ballroom or a country club, chances are the dress code will be more conservative.

· Embrace color. All black on a wedding guest is too severe. Jewel tones like peacock blue and emerald green and ombré patterns are sophisticated and vibrant. Stay away from white, not just at the reception but at any wedding event, from the rehearsal dinner to the day-after brunch. That's the bride's territory.

· Stay focused. Choose one item to build your outfit around, whether it's your shoes or an amazing piece of jewelry. You want to avoid looking as if you piled on every accessory you own. If you have a complicated dress with a lot of ruching or a bold print, keep the jewelry minimal. And those dyed-to-match shoes are a definite no-no—not everything needs to coordinate exactly.

· Don't go flat. Heels are tricky at an outdoor wedding, but flats don't feel right with a formal dress. Wedges are great for lawn receptions. If a wedding is on sand, I wear embellished sandals, though I often take them off and go barefoot.