Plan to travel in the off-season. This might mean cruising with Disney in the middle of the winter, no matter where the trip originates. Check weather forecasts and patterns in the ports you'll be visiting to avoid hurricanes or rainy seasons. Disney cruises are less expensive in the off-season because children are in school, and travelers are less inclined to take a vacation when faced with the possibility of less than perfect weather.
Consult with a variety of travel agencies. Since a Disney cruise is a popular vacation choice, a travel agent should be able to quote you a price with little trouble. Companies that do a lot of business with Disney may be able to negotiate a special rate for you.
Book your cruise with friends and family. Not only will you have extra fun with the people you care about, you can negotiate a better rate if you're bringing more cruisers to Disney. Talk to your cruise booker about package rates for groups. You usually need to book 10 to 15 people to qualify.
Look for deals with travel agencies or coupons that will offer you on-board credit. Some travel agencies give you up to $600 in on-board credit just for booking with them. Save a large chunk of change by walking onto the ship with money already earmarked for the voyage.
Check the "Disney Cruise Special Offers" page at the Disney Cruise Line website. Deals change all the time, but as of April 2011, there are inexpensive rates offered on a seven-day European cruise, as well as discounts for Florida residents and military personnel.