Resorts in Mexico (Visitloscabos.travel) and Puerto Rico (Gotopuertorico.com) are busiest during the colder months, so you'll find bargains and openings now. "Mexico is coming back from a tough year," says Gaines. "So everything will be in deep discount through the summer." Also, keep hurricane season in mind (June 1 to November 30, but most storms hit from late August to mid-October) and take advantage of the low rates during this time. A week in advance, you can get a pretty clear picture of the weather, then zero in on super-cheap places.
Land a short-notice cruise
Cruise lines get desperate to fill their beds about a month before setting sail. How desperate? A rate of $100 a night per person is not uncommon. "I'm also noticing a lot of on-board promotions," says Gaines, like $200 credits. Check out Cruises.jetblue.com or Cruisedirect.com.