Well, my father is a lawyer. So that means we're well-off. My parents bought into DVC when I was 3 and have managed to save money that way (don't ask me how, my dad is the one who has the system down to a science). We get discounts and such from that, plus it means the room is basically paid off. We get annual passes which gives even more discounts and since we go so much, it gets us about two to three trips in. My dad I believe belongs to a few rewards programs. And other than that, we're just wise about money when we're at home. Ya know, don't spend it needlessly, don't eat out except for crabs occasionally and baseball games, don't get expensive cell phone plans, don't go to the movies a ton, basically save money where we can. When we're away at WDW, we find ways to save. My dad gets the Tables in Wonderland card which saves us on meals. We don't buy a ton of souvenirs. Mostly my brother and I get shirts down there, which we need anyway (seriously, I don't know when the last time I went shopping for non-dressy shirts was) and artwork on occasion. Instead of getting the two bedroom MK views at BLT, we get the studio with the standard view to save points. Just little things that add up. We're able to afford two-three WDW trips per year and four vacations total.
EDIT: I forgot. Dad also invested in Disney stock and we all have Disney Visas, which somehow gives us extra rewards. And we usually fly Southwest, a company that my dad has down to a science.