Need to get away? If you are flexible, last minute deals for cheap flights are always available, but you have to be adventurous. You need to be ready to go in as few as a couple of days. You life style has to be elastic enough to accommodate a quick departure. In addition, you cannot have your heart set on a destination that requires a visa. You probably won’t have enough time to acquire one. Make sure your passport is valid and any other papers are up to date, like an IDP (International Driving Permit) if you plan to rent a car and drive yourself.
Next, cultivate several travel agents. Travel agencies do a lot of business by booking tours. Some are air based, some cruise lines. Cruise lines are notoriously under booked in off-season. You can call the cruise line directly to see what is departing in the next few days from just about any port of your interest and ask if they are under booked. If they are, find out what kind of deal they will cut you. They might be able to help with airline discounts to get you to the port.
Talk to a travel agent for deals they need to close in the next day to week. Ask about off-season destination deals. For instance, prime travel for the Caribbean is November to March. However, places like St. Martin have the same temperatures in June and July as December. You could spend a week at the Jersey shore, or at Margot, St. Martin for about the same price. The travel agent will know what hotels are good and are looking to place people in rooms. They might a have a pre-set package that needs to be filled, or can set one up with venders in the area they work with all the time. It is a win win. They make points with their venders and you score discounts and upgrades that would be expensive in the regular season.
Lastly, check the aggregate sites like this one for cheap flights. Then contact a travel agent for any deals they can swing for under booked accommodations. This way you get to pick where you want to go, but you still need to be flexible enough to work with the travel agents for the best deals.