Don’t be afraid to add all the juices from the canned beans and tomatoes, as well as some additional water when you’re mixing up the meat mixture. You want plenty of moisture in the meat mixture when it goes into the oven - the Fritos absorb a lot of moisture and you don’t want it too dry.
This dish has some spice to it. To reduce the spice, use canned pinto beans instead of the Ranch style beans and/or regular diced tomatoes instead of Rotel tomatoes.
A can of corn can also be stirred in with the meat and bean mixture.
Other toppings that would go great with this casserole include chopped cilantro, raw bell peppers, sour cream, and avocados.