When to Reserve What

The idea is that if you know exactly what you want — and won't settle for anything less — it's best to book well in advance. Not picky? With a little flexibility, you'll find last-minute booking deals for just about everything.

But the best bargain hunters know to look for that sweet spot of good selection and low prices. We talked to the experts and found the best time to reserve everything from moving companies to summer camps.

Why: Contractors are busy working year-round, but the real flood of calls for bids on new jobs occurs in spring, says Vince Butler, past chair of the National Association of Home Builders' Remodelers Council. "Someone calling in the middle of the summer is going to get a lot more of the contractor's time," he says. With emptier schedules during the fall, contractors face increased competition, and thus have more incentive to negotiate.

Why: Not every location offers last-minute rental deals, cautions Phil Reed, consumer advice editor for Edmunds.com. In fact, most car-rental agencies increase their prices seven days out from a given rental date. Book before that for low prices and decent selection.

Why: That's when the cruise lines release their schedules and begin booking for the following year, says cruise broker Stewart Chiron, a.k.a. The Cruise Guy. You'll find the cheapest prices for those routes with the widest availability. "The trend for the past several years is that prices go up dramatically as the cruise date approaches," he says. "As cruise companies see demand go up and supply go down, they increase prices. Prices just go off the charts."

Why: Hotel rates fluctuate based on demand, says Robert Mandelbaum, director of research for PKF consulting, a hotel-industry research firm. Generally, prices get lower closer to your check-in date as the hotel looks to fill empty rooms, he says. To get the best rate at the hotel you want, book as far in advance as you can, and then check in every week or so. "Most hotels will let you cancel, penalty-free, until 24 hours in advance of your stay," says Mandelbaum. "If you spot a lower rate, cancel your old reservation and then immediately rebook it."

One caveat: Do check that the rate is refundable before you try this book-and-rebook trick. Thanks to online price competition, more hotels are adding low-cost restricted rates to their rosters, says Mandelbaum. Canceling these will cost you at least one night's stay, if the rate is refundable at all.