If you're going on a trip and plan to visit some of the big museums, ask your local children's librarian for some book recommendations to help prime the pump. Younger kids will be dying to see Monets in person after reading Linnea in Monet's Garden, and any visit to the Met would be well-preceded by From the Mixed-Up Files of Mrs. Basil E. Frankweiler, about two kids who spend the night in the museum and solve a mystery. (Just make sure no one tries to stay behind when you leave.)
Pack snacks (almonds, string cheese, fruit leather), or decide in advance that you're ok with dropping some cash in the museum cafe. Walking around on those hard floors is tiring, and it's important to keep everyone's blood sugar up. In nice weather, many museums have spaces where you can picnic. (The Museum of Fine Art in Boston, for example, has a lovely courtyard just off the main cafeteria.) But even if there isn't a picnic space, call ahead and see if you can bring your own food into the cafeteria.
When you arrive, give each child his or her own copy of the museum plan. If you have more than one child, let each one pick a gallery they are excited to see. Visit those galleries first, then decide whether the group is up for a more. Avoid a dictatorial approach and make it feel like a real group activity, with everyone getting to see the thing they care about most. Remember, keeping trips shorter and avoiding over-tired meltdowns will make each subsequent trip easier and more fun. Consider a family membership to any local museums you might visit a few times a year. The cost often evens out after just a couple visits, and since you aren't paying a set amount each time, there's less pressure to stay for as long as possible.
Finally, how about a bit of smart bribery? While offering rewards for everyday good behavior might not be the best tactic, a bit of well-handled bribery can be a lifesaver on trips. Lifestyle blogger Lisa Borgnes Giramonti is the kind of jetsetter we all dream of being, and she's perfected a few tactics to keep her 7-year-old son happy on trips to places like a museum of 18th-Century interiors. Her brilliant advice: Instead of waiting until the end of a museum visit to check out the gift shop, try dropping in at the beginning of the trip, and letting your kids choose a treat that they'll receive at the end, provided that they've behaved well. (Never underestimate the power of a model dinosaur or space ice cream.) Other things that work: She always lets her son navigate them through the museum, and while they are in the gift shop at the beginning, she lets him pick out a handful of postcards. She then asks him to find those pieces in the museum, making the trip a "treasure hunt." Bonus: Lisa keeps those postcards as a record of their trips. As she wrote in a recent blog post, "If anyone had told me that my son would be grabbing my elbow and shouting, "Mom! We need to find the Elizabethan Portrait Room!" I would have told them they seriously needed to up their medication."
Now that's genius.