Fair enough, but what if you could put more of that money toward having fun, and less toward the nuts and bolts of getting from Point A to Point B?
One way to save is to turn your vacation-planning process on its head. Instead of dreaming about particular destinations and then hunting for deals, take advantage of trip-planning sites such as Hopper, Adioso or Google Flights. They'll map out for you, based on your home airport, which locations are more of a bargain. Timing matters, so you can opt to narrow results for a particular week—or let the site tell you the best days to go.
Read MoreIs American Express Platinum the best travel credit card?
There's also a missed opportunity if you're not quadruple-dipping for rewards. That means rewards from the hotel or airline, plus rewards from a booking site and credit card. Then make sure to link to the booking site through an online mall such as FatWallet or BeFrugal, to get extra cash back. Stacked up, you could get 10 percent back for travel expenses.
Read MoreWhich membership pays off: AAA or Amazon?
If you're staying close to home this summer and looking for some cheap entertainment, consider a family membership to a local zoo or museum, or a season pass to a nearby amusement park. Do the math on those purchases, and you'll typically find that they pay for themselves on the second visit.
Many also offer wider access than just that one location or park. For example, members of a museum that's part of the Association of Children's Museums pay reduced admission to sister museums around the country.