Include a Sunday night in your stay.

"Many hotels get Friday and Saturday night bookings from leisure travelers and Monday-through-Friday traffic from business travelers, so there's a big void on Sunday night," says Brian Hendricks, marketing director of Quikbook, the hotel consolidator that offers discounted rooms—mainly at non-chain hotels—in large U.S. cities. Instead of going for Friday and Saturday nights, he advises, book Saturday and Sunday or Sunday and Monday.

Call the hotel directly and speak with its reservations desk.

While less-expensive hotels use an off-site call center to handle phone bookings, top properties have an on-site reservations staff that is more customer service oriented and empowered to help you. The finer the property, the more important it is not to book until you've had a conversation with a reservations supervisor. Hotel rates are largely determined by occupancy levels (hotels with many empty rooms are generally willing to offer enticing rates) so your first goal in phoning the hotel is to figure out when it will be emptiest. If your dates are flexible, be point-blank honest and say, "I'd like to stay at your resort. I have this 20-day window. Could you tell me which dates have the lowest rates?" Also ask, "If I come on that date, would there be a chance of an upgrade?" Never settle for the first price quote you're given. Bring the reservations agent down the hotel's rate ladder by asking repeatedly—in different ways—whether there is a better price: Ask if there is a rate lower than what you found online. Ask if there is any special promotion for your particular dates or if another room category has a better rate. "You might be surprised how often a better price or an upgrade might be offered in an effort to ensure you book that room," says McDavitt. If you're a past guest of the hotel or you've stayed at a sister property, absolutely mention it. And, of course, it always helps to charm the reservations manager.

Before booking a hotel package that includes free extras, do the math.

Add up the monetary value of the free components that you know you will use (meal credits, activities, etc.). Packages that include additional free nights usually represent some of the best opportunities to save. Any package that comes with a club floor upgrade can represent a substantial savings too—especially if you're traveling with children. At Ritz-Carlton properties, for instance, staying on the club floor—which normally costs a premium of $100 to $200 per day—means access to many perks, including a club lounge that serves meals, snacks, and drinks all day and well into the evening. "There's no reason why a family of four can't stay on the club floor without ever having to eat in a restaurant," says Deuschl. Whatever package inclusions a hotel promises, "make sure the value is worth it," warns Brancatelli. "On top of a lot of good deals, we'll see a lot of bad deals masquerading as good deals."