Plan to travel in an off-peak season. Disney considers January through early February, August through September, and the first two weeks of December its value season, and room rates can be dramatically lower then than at peak times. Exact dates vary each year. Disney often offers a free dining plan for travel in September, but weigh that against the huge crowds that turn out for this promotion.
Find a discount code. Disney often releases promotional codes through travel agents, newspaper ads and more. These can be found in numerous places online, but one of the best sites for them is mousesavers.com. You may also book discounted rooms through AAA if you are a AAA member.
Choose your park tickets. If you will visit only one park per day, the cheapest option is the single-park tickets. Park-hoppers cost more, but add flexibility. Skip the no-expiration option. Not only is it expensive, but there's always a risk you'll lose or forget your tickets before the next trip. If you are planning a longer trip, compare the cost of tickets against the purchase of an annual pass, which can also get you discounts on room rates. AAA offers discounts on Disney park tickets.
Skip the meal plans. To really do Disney on the cheap, eat breakfast in your hotel room and choose counter-service meals in the theme parks. A number of delivery services such as gardengrocer.com will deliver groceries to your hotel room. Again, check for discount codes and coupons before you order.
Call a travel agent. Just before you finalize your reservations, call a travel agent who specializes in Walt Disney World. Tell her what you've booked and how much it will cost, and see if she can beat it.