If your summer plans involve sharing your vacation with another couple, or their entire family, a little advanced planning will help to ensure that your friendship remains intact, long after your plane lands or car comes to a stop. Here are 12 tips that will get you and your spouse off to a good start.

Talk money. Discuss how everything will be divided up before you start spending money on things like airline tickets. In developing your budget, be sure to include all costs for transportation, food, lodging and entertainment. If you are traveling by car, decide who will drive, how you will divide the cost of fuel and whose vehicle you will use?

Hash out travel preferences. Once at your destination, will you opt to use the subway while your friends prefer to take a taxi? Are you a hot dog and soda type of couple while your friends prefer fine dining and small, exclusive bistros? The cost difference is substantial so this is an important topic to address.

Anticipate airport security. Seriously, you know the drill at the airport, so don’t act surprised when you are strip searched because you are packing scissors, a utility knife and two pair of tweezers in your pocket.

Party animal or party-phobic. Are you the type who will skip dinner in order to get straight to drinking and dancing, while your friends prefer to share an early bird special and go to bed with the chickens? Better to understand your social "likes and dislikes" before making reservations for four at that exclusive hot spot, which requires a credit card deposit and your finger prints to get in.

Fish stew and grouchy friends don't travel well. It’s no fun to get stuck in a hot car with either, and it’s worse when you are subjected to hours of complaints and negative remarks from travel mates who are not as travel friendly as you and your spouse. Take a good, hard look at your travel companion’s personality and decide if you are a travel fit.

Anticipate problems. There is no doubt that something will go wrong during the vacation, and packing an open mind and good attitude along with your string bikini and your husband's Speedo are a good idea. (Just joking about the Speedo!)

Assign duties. If you are sharing a condo at the beach or a cabin in the woods, it would be a good idea to decide who will wear the chef's hat and who will swat the bugs. If everyone pitches in, sharing tight quarters or a huge living space will be more enjoyable for everyone.

Schedule alone time. Just because you are traveling together doesn't mean you must be attached at the hip to the other couple. (That also applies to your spouse!) Everyone can benefit from a short break.

Surprises aren’t always fun, especially when they come in the form of unexpected guests such as children, pets and extra friends. If not included in the original travel plan discussion, don't assume they will be welcome without asking first. Don't be offended or surprised when your friends nix the idea of your three kids during their own "no kids" vacation.

Put all your cards on the table—annoying habits, that is. If you snore so loud you wake the dead, or your wife has an incessant habit of cracking her knuckles to the tune of Yankee Doodle, spill the beans sooner than later.

Shopping or museums? While you are online checking out all of the historic points of interest, your friends may be online checking out all of the summer sales. Again, communicate your interests and don't be afraid to go your separate ways. A small dose of both is a friendly compromise.

Pack smart. If you are going to Niagara Falls, don't leave your tennis shoes in your closet and assume your friends will have an extra pair. If you need a blow dryer, pack it or plan to buy one when you get to where you are going. Don’t assume your friends will pack necessities that you can "borrow." Conversely, if you plan together, you can both pack lighter.

And finally, get a goods night rest the night before you leave so you can start your vacation on the right foot. Nothing spells trouble more precisely than waking up late, packing at the last minute, forgetting your medication, realizing your car needs gas and missing your flight. And, remember to have a great vacation.

Diane Gottsman, a nationally recognized etiquette expert, is the owner of The Protocol School of Texas, a company specializing in etiquette training for corporations, universities and individuals, striving to polish their interpersonal skills. You can reach Diane at 877-490-1077 or www.protocolschooloftexas.com.