Preheat your oven to 350°F (175°C) to crisp the tostada shells.
Warm the refried beans in a small saucepan over medium heat until heated through.
Place the tostada shells on a baking sheet and warm them in the preheated oven for about 5 to 7 minutes until crisp and slightly golden.
Spread a generous layer of warm refried beans on each crisp tostada shell.
Layer sliced avocados on top of the refried beans.
Top each tostada with mixed shredded iceberg lettuce and red cabbage for crunch and color.
Sprinkle crumbled Cotija cheese over the greens.
Season with a pinch of sea salt, then add chopped fresh tomatoes, Pico de Gallo, or salsa. Drizzle with Mexican crema or Cilantro Lime Crema.
Optionally, top with pickled jalapeños or pickled serrano peppers for heat, then garnish with fresh cilantro leaves.
Serve with lime wedges on the side for an extra zing.