We aren't big breakfast eaters so we always pack a few things to eat quickly in the mornings, and often things that can be eaten on the go, as hitting rope drop for EMH is important to us. (Think granola bars, applesauce pouches, pop tarts which my kids eat cold.) I will bring in a few snacks for the kids, mostly so if they are hungry we don't need to stop immediately to get them something, but nothing that needs to be kept cold. Past that, I am not about cooking meals or bringing meals into the park with me. That's not a vacation to me. We also travel at the end of August when it's HOT. We tend to eat less at meals and put more towards getting snacks (usually ice cream or something cool) throughout the day.
For us, the keys are 1.- none or very few character meals or all you can eat places. The per person price is crazy for my now teen girls who don't eat that much. 2. We also either share meals, or the teenage girls order kids meals. It's either one or the other, mostly because if we don't we ALWAYS have food we end up throwing away. For CS, Pecos Bills was great for sharing as was Casey's Corner (we got the large hotdogs with mac and cheese on it with fries, and 2 people couldn't even finish one meal!), Comic Rays and Flame Tree BBQ. 3. We like to do sit downs almost every day. For sit down, look at menus ahead of time and choose somewhere with reasonably priced entrees. 50's Prime Time, Sci Fi Dine In, Plaza, Yak and Yeti, Via Napoli (if you share pizzas) were pretty good values for the price and food you got (I'm sure there are others). 4. Doing more Counter service and less sit down can save you money. Look at places like World Showcase, Sunshine Seasons, Be Our Guest lunch, Santuli Canteen, Columbia Harbor House for some more interesting food choices at a decent price (besides the price, you're also saving money on not needing a tip!) I also feel like the restaurants at Disney Springs are a little more reasonably priced than the parks. WE love Earl of Sandwich there. Blast pizza is there too, D-Luxe Burger could be a reasonable meal too, the burgers are large.