We drive. We put gas on bank cards, so really we just pay for snacks/meals on the trip, plus snacks/meals/souvenirs while we're there. We're DVC members, so that takes lodging costs out of it for us. We don't usually do dining plans in the past (except for one trip). We budget $150 to $200 per day for the family of 4. We pre-plan where we'll be for which meal, so we know that a day that includes a LeCellier dinner is gonna be a lot more than a Chef Mickey breakfast day. That works for us pretty well. We tie the room reservation to a bank checking card. We have Internet banking so we can tell pretty well where we're at. Cash on hand is usually around $200 for incidentals.
We either do breakfast in the room, with a big mid-afternoon 'lupper' meal in park, and then late snacks or a pizza at the resort. Or we'll do a big breakfast in the morning, counter service/snacks for later in the day. We tend to eat heavier in WDW than we do day-to-day. Our kids have their own savings, which we supplement ($50-$100 for each kid for the whole trip). I get myself a big
LEGO set, a DVD, a game, or a book; my wife will get herself clothes, jewelry, etc. Kids get themselves toys and their own candy for home, and we usually get them shirts and hats. We take a backpack with iced water, pop tarts/breakfast bars, & cracker packs with us every day.
My son is 11, so he's now at a higher price for meals. We'll do a dining plan this next time.
We do Disney cheaper than some, more expensive than others. We eat well (I personally feel like I overeat some days), we don't deny ourselves much, but we also don't leave with $1000 art pieces either.