In a mixing bowl, combine shrimp, olive oil, garlic powder, cumin, paprika, salt, and black pepper. Toss to coat evenly.

Heat a skillet over medium heat. Add the shrimp and cook for 2-3 minutes on each side until pink and cooked through.

Place the tostadas on a baking sheet. Top each tostada with a generous portion of cooked shrimp.

Add shredded cabbage, diced tomato, chopped red onion, and cilantro on top of the shrimp.

Drizzle with lime juice and add avocado slices. Serve immediately.