You've played dress-up in bridal boutiques, tasted tarts and tartare, sipped rose with a sommelier, and picked the perfect peonies for your bouquet. And the ceremony site, reception locale, and first song? Check, check, and check. But even if you have the details down, there are still parts of the planning that require more than playing a game of favorites. These decisions usually have to do with etiquette, that age-old art, and demand patience and diplomacy. Before you decide to go strictly by the rule book, though, remember that there's a difference between traditional etiquette and modern manners. It's always good to be familiar with the former, but the latter might be a better fit for the forward-thinking bride. Where appropriate, we reference both points of view so that you can make an informed decision.

In the end, "you should be your most gracious, beautiful self at your wedding," says Marcy Blum, a wedding planner in New York City. "You want your guests to look back and think the day was such a dream" -- even for them. Here's how to navigate party pitfalls while minding your manners.

You're worried that a couple of your friends will show up with dates even though they weren't invited with them and though children weren't invited, you have a sneaking feeling one of your friends might bring hers. What can be done about the crashers? 
You should make all guests who walk through the door -- even if you did not receive a reply card from them or if they were not invited -- feel welcome. "There will always be enough food and enough booze," says Blum.

In fact, always assume that you'll have more people attending than replied, says Hotchkiss. "Oftentimes, a reply card will get lost in the mail, or someone will think they replied when they didn't." Tell the person in charge of your venue that you'd like two to four extra place settings ready, just in case. And if you're renting, always order three to five percent more of everything than the number of guests who RSVP'd yes, says Hotchkiss. (Besides being prepared for an extra guest or two, you'll also be covered in the event a chair breaks or a napkin rips.) Don't max out every single table, and it will be easy to squeeze in an extra chair or two. 

If you're at the stage where many of your friends have little ones, and you're determined to have a grown-up affair, be proactive. Don't mention children's names on the invitation; include a card that says, "Children are welcome to the ceremony. During the reception, they are expected in our kids' hospitality suite." You may want to have individual conversations with parents you think may have a problem with this. "If you know them well enough to invite them, then you know them well enough to call them up and discuss the matter," says Mac Adam. Suggest babysitting services in the area if it's a destination wedding. But if someone brings their kids regardless? Ask the person in charge of the venue to plate a child-friendly meal -- plain pasta, perhaps -- and arrange for an extra chair at the table. Then take a deep breath and go back to enjoying your party. 

Just as common as an unexpected guest is an unexpected no-show. If someone cancels last minute, always make sure to have the staff remove the place setting and chair, suggests Tara Guerard, a wedding planner who splits her time between Charleston, South Carolina, and New York City. The feeling at the table will remain intimate and lively as long as no one has to talk over empty place settings.

Your circle of friends is large, and you have a wedding party to match. To show them how much you appreciate all they've done, you want them seated with you at the head table. There's just one problem: That leaves no room for dates.
"In traditional etiquette, it's absolutely acceptable to split someone from their date," says Elise Mac Adam, author of "Something New: Wedding Etiquette for Rule Breakers, Traditionalists, and Everyone in Between" (2008, Simon Spotlight Entertainment). "But if you're sensing there's friction, you should rethink your plan."

In fact, allowing your bridal attendants to dine with their dates is a foolproof way to keep them happy and to keep the bash lively. "If there's a huge wedding party, seat the best man and his date and the maid of honor and her date with the bride and groom," says Blum. "Then sprinkle the rest of them at tables across the room to be ambassadors." As for showing your appreciation? Putting their happiness first will send the message clearly. After all they've done for you, they deserve to kick back and enjoy themselves post-ceremony.