DO: Get the hell out of Boston. There are only so many times you can do the Freedom Trail and all 99 flavors of Sam Adams beer start to taste the same after a while.
DON'T: If you're Bostonian escape plan involves Martha's Vineyard, don't assume you can just show up and get on the next ferry. This applies even if you have researched the itinerary (and printed it out), mapquested the route and timed it just so in order to arrive with sufficient time to purchase the tickets. You (or more precisely whoever is driving the car) will get hosed. The reason for said hosing is that the parking for the ferry is nowhere near the actual ferry, a fact that is conveniently omitted from most travel sites. Therefore the driver will have to drive back from whence they came to park the car (or seeing as we are in Massachusetts to "pahk da cah") in a remote lot and board a bus that will return them to the spot where a ferry once stood.
DON'T: Leave your friends behind at the ferry terminal with the assumption that they could not possibly leave without you. We could and we did.
DO: Grab an outdoor seat on the ferry. It may be a bit chilly but chances are you are coming for the scenery, which is best appreciated without a window between you and it. Added bonus: the school groups tend to congregate in the cafeteria, so this is also a good way to stay as far away from them as possible. Added added bonus: You might see a rainbow.
DO: Enjoy the window shopping when you disembark in Vineyard Haven. From what I could see, that is the main thing to do there. Chances are, unless you are one of the celebrities whose name appears every time you google Martha's Vineyard, you can not afford anything but it is nice to look around, just the same.
DON'T: It is a bad idea to assume that just because your ferry dropped you off at Vineyard Haven that the one departing an hour later, the one carrying your disgruntled friends who were too busy dropping off the car to join you earlier, will do the same. This assumption could lead to a very last minute realization and a mad dash across the island to Oak Bluffs (aka "the other ferry terminal").
DO: Grab a free walking tour map. This will come in handy in Oak Bluffs by leading you to the so-called "gingerbread houses". These were originally tents set up by people coming to attend religious revivals, which were held in a larger, apparently less picturesque tent.
As people started staying for longer periods of time, the tents sprouted floors, walls and eventually ceilings, all based on the only blueprint they had on hand by the renowned architectural firm of Fisher-Price. (That last part was not stated in the walking tour guide but it is clear that it was either that or the foreperson on the project was a frustrated baker).
DO: Once you have accepted that the west side of the island is not happening and you have reunited your entire party, head over to Edgartown, a village which once played the part of Amity in the original Jaws movie. Originally a whaling town, it is now home to a bunch of Federal-style mansions, art galleries and one not-so-remote lighthouse.
DO: Kick back and enjoy the day. It could be worse. You could be in Boston.
DON'T: This should go without saying, but do not miss the return ferry. If members of your party try to order big meals 30 minutes prior to the last ferry departing, yell at them. They will understand. Eventually.