Try to find a locale that isn't overrun with visitors and tourists on the Fourth. You'll have more fun, get first choice of accommodations and not have to wait for hours at the best restaurants.
It's best to find a locale within reasonable driving distance, as well, particularly if your time is limited. Nobody wants to spend half their vacation in a hot car trudging through traffic, and you'll save gas money.
Aim for a coastal location or one by a river if humanly possible. It's not much of a summer getaway if you can't beat the heat by taking a dip.
Don't forget the summer essentials like a picnic basket, suntan lotion and either a kite to fly or a Frisbee. The Fourth is all about getting out in the sun to have some fun.
The Fourth is also about BBQ'ing up a storm, so try to find lodgings (or a park) where you can bring a cooler full of meats and treats to cook up. Don't forget the extras like sauce, potato salad and the like.
Indulge in the local activities where you're visiting, be it a clambake or a grange hall dance, or just the local fireworks display. You'll meet nice people, have a good time and get to savor what the area is all about.
Be careful when it comes to setting off or standing near serious fireworks. Better safe than sorry when it comes to pyrotechnics, and even the highest-quality skyrockets and roman candles can occasionally be defective.
Do something patriotic on your trip, even if it's just reading a copy of the Declaration of Independence on your drive or listening to a book on tape about Benjamin Franklin. This is America's birthday after all!