01 - Combine shredded chicken with chili powder, cumin, garlic powder, salt, and lime juice in a mixing bowl. Mix thoroughly and allow flavors to meld.
02 - Heat refried beans in a small saucepan over medium heat until warm and smooth, stirring occasionally.
03 - Spread a thin, even layer of warm refried beans onto each tostada shell.
04 - Top the beans with the seasoned shredded chicken. Layer lettuce, diced tomatoes, red onion, and cheese over the chicken.
05 - Garnish with sour cream, cilantro, jalapeño slices, and avocado. Serve immediately with lime wedges on the side.