Weddings are special occasions, but they're also ripe for blunders if you're not paying attention. But if you know wedding etiquette -- "weddiquette" -- you'll be able to avoid big-day faux pas.

*'Perfectly Polite Wedding'

Nationally known etiquette consultant Jodi RR Smith of Mannersmith Etiquette Consulting wants to help couples have "a perfectly polite wedding." She says couples already know many of the faux pas, which is why she says it's so important to communicate expectations ahead of time.

For example, if you're hosting a simple ceremony followed by a cake and Champagne reception, let guests know what to expect. "Your invitation must make clear that is what is happening," says Smith. "No guest should arrive expecting a sit-down dinner and dancing until the wee hours of the morning."

*Be a Good Guest

Guests need to follow some basic wedding etiquette rules too, including being on time and giving a gift. Note that the gift doesn't need to be the price of the guest's meal.

Be sure to RSVP in a timely manner. If something changes and you cannot attend the wedding or you need to leave early, let a couple know ahead of time.

"As a wedding planner for 14 years, I learned to anticipate the guest count reducing by 35% to 65% after the meal was served, which is such a rude move to the couple and their parents," says Amy McCord Jones of Flower Moxie. "If you cannot stay through the entire event, let the couple know that you can only attend the ceremony and will be leaving afterward so they don't pay a catering and bar fee for your presence."

Dress up, too. It's always better to be overdressed for a wedding than underdressed. Remember, even an informal wedding is a special occasion, and you should look the part.

Jones advises guests to be present and in the moment. That means put away your phone, don't chat with your neighbor, and pay attention, especially during the ceremony and important moments of the reception.

"I've felt so heartbroken for my clients when they have paid thousands of dollars only to look out at the guests to see no one cares that they are cutting their cake," says Jones.

Guests should be on their best behavior too, including not getting into disagreements with other wedding attendees and not stealing the spotlight from the couple.

*Be Social

Social media can be an issue for both the couple and their guests. Newlyweds shouldn't over-post their planning on their social media, especially since guests may then feel seeing wedding details, like the flowers, food or fashion, aren't special. On the big day, limit how much you post too so you can enjoy the day. After that, post as you see fit.

Guests need to be even more considerate about wedding photos.

"Don't post photos of the couple until they've had the chance to post their own chosen photo, unless you are explicitly told otherwise," says Jones, noting it's OK for guests to post pics of themselves and their friends at the celebration. "Couples have invested months and thousands of dollars into their wedding day, so posting and tagging an unflattering, unedited snap of the bride is a no-no!"

*Handling Sticky Etiquette Situations

As a couple, do your best to prevent wedding day drama. That means you should have someone keep an eye on attendees who drink too much; hire a babysitter for guests with kids; and review your contracts to see what's included and what's not, such as tips for the musicians.

Then relax (if you can), knowing you've done your best. How will you know if weddiquette rules have been followed?

"If the couple hosts a wedding where everyone feels included and comfortable, then they did a good job," says Smith.