1. White Is Not Right  It seems obvious and yet so many guests seem to forget. Material that is mostly white with a small pattern is a no. White suits are a no. If there's a question...no. White garb is meant for one person only and that's the bride! Always. End of story.

2. Skip the Shorts  Shorts at a wedding? It's just wrong; even if you dress them up with a blazer or a pair of sexy heels. Guys, no matter how preppy you make 'em, and, girls, no matter how stylish Charlize Theron looks in them, shorts just won't do at this affair.

3. Keep it Classy  Up-to-there miniskirts, shirts with more buttons undone than not, and bustier tops are best left for a night out with the girls (or that person you really want to wow). We know you're sexy, you know you're sexy, but a wedding isn't the place to show off. Play down the sassy and play up the classy.

4. Coattails Don't Cut It  If it's a black tie wedding, men are going to be renting a tux or digging one out of storage, so tap into your inner James Bond. But keep it in check -- a classic or modern-cut style is the best bet. Stay away from extra frills like tails, ruffles, loud colors, or satins which are inappropriate and overly fancy. Even if you plan to be the funny man in a powder blue '70s number, refrain. All attention should be on the groom (and his tricked-out honey, of course).

5. All That Glitters Is Not Gold  Stay away from anything lamé, sequined, shiny, or glittery. It's distracting (both in person and in those precious keepsake photos). Again, the newlyweds are the star attraction, so resist the urge to be a "shining star."

6. Lose The Leather  Leather rocks (where would our shoe collection be without it?!) but it's not the best choice for anything above the ankle on a day of "holy matrimony." Leather jackets and skirts are probably too casual, and leather pants are just too flashy. Even if the bride and groom are hip enough to roll with it, opt for something more sophisticated.

7. Mad Hatters  Whether you wear a baseball cap to show your allegiance to the A's, disguise thinning hair, or hide a bad hair day, a wedding (even the most casual summer ceremony) is the last place to don one. Go hatless and hit a home run!
 
8. Give The Wild West A Rest  Bandanas, cowboy boots, and ten-gallon hats all make it onto the list of what not to wear. Unless the betrothed couple has planned a themed bash and requests that guests get decked out in ranch gear, save these goodies for another day, pard'ner.

9. Dress to the Nines  Don't be too cool to don your finest fixings. Honor the couple's union by leaving your jeans at home -- even the really nice ones! Unless the invitation mentions a beach barbecue or luau, forego the casual fare and plan on turning it up. It's a wedding after all!