Begin by rinsing your black beans and placing them in a medium sized bowl. Season with taco seasoning and combine until all black beans are coated. Heat in the microwave (or on the stove) until warmed through. Set aside.
Warm and season corn to taste. Set aside.
Mash and season avocados and set aside.
Begin building tostadas, starting with the shells, then add guacamole as the base. Next add the black beans, corn, and remaining veggies (tomatoes, red onions, and cilantro).
Drizzle with Good Karma Ranch Dip and garnish with cilantro. Enjoy!