01 - Combine shredded chicken with chili powder, cumin, garlic powder, salt, and lime juice in a mixing bowl. Mix thoroughly to ensure even coating and set aside.
02 - Warm the refried beans in a small saucepan over medium heat, stirring occasionally until smooth and spreadable.
03 - Arrange tostada shells on a serving platter. Spread a thin, even layer of the warm refried beans onto each shell.
04 - Top the bean layer with the seasoned shredded chicken, distributing it evenly among the shells.
05 - Layer the lettuce, diced tomatoes, red onion, shredded cheese, sour cream, cilantro, jalapeño slices, and avocado slices over the chicken.
06 - Serve immediately with lime wedges on the side for squeezing over the top.