6. Buy a "Tables in Wonderland" Card
The "Tables in Wonderland" membership is one of those things that doesn't seem to get brought up nearly as often as the Disney Dining Plan does. Which is strange, because it can be a pretty good value if you play your cards right.
Open only to Annual Passholders, Florida residents, and Disney Vacation Club members, each "Tables in Wonderland" card allows up to ten guests to get 20% discounts on all food and beverages (including alcohol!) at participating restaurants throughout WDW, along with some other benefits. If your annual food budget at WDW is high enough—namely, if you eat primarily at their table-service restaurants—you'll find that this program can pay for itself after a while.
The card costs $175 for Florida residents and $150 for Annual Passholders and DVC members. Is it worth it? You'll have to do the math on your own budget to know for sure.