Flights - I have a JetBlue Amex (soon to be JetBlue Mastercard, as they switched partnership companies) that I use for everyday purchases to accumulate points for flights. I also fill out surveys on sites like E-Rewards and Points for Surveys. Between these methods I can eke out two-three round trips tickets a year.
Tickets - I always bought through Undercover Tourist to save a little money until I went with an AP. I honestly should have bought an AP 2-3 years ago with how often I was going, but there were a number of last minute trips in those years so it didn't occur to me at the time. Even at the higher price point, an AP made more sense cost wise considering how often I visit, and the fact that I park hop so much.
Hotel - I typically travel during the off season when rates are slightly cheaper, and I stick to the value resorts.
Dining - I currently have Tables in Wonderland, and while it made financial sense this year, I won't likely renew next year even if I renew my AP. Having been as often as I have, I know what menu items I like or don't at most places I visit, so using online menu prices I have a very good idea of how much I'll spend on food and keep a running spreadsheet. If you need to save on food, there are plenty of ways to do so, from having groceries delivered to your room to doing QS only and sharing meals. Heck, when I was in college I literally had one trip where I subsisted mainly on Mickey Bars (though I don't tend to recommend that approach, lol).
I also don't rent a car and use only Disney transportation (and a cab/Uber if I have planned a Universal day).