
Make the shrimp. Pat the shrimp dry with a paper towel to remove any excess moisture. Add to a medium bowl and toss with salt, garlic powder, onion powder, paprika, chili powder, and black pepper until evenly coated.
Melt the butter in a large skillet over medium heat. Add the seasoned shrimp and cook for 3-4 minutes, until plump and pink. Transfer to a bowl and set aside.
Make the mango pico de gallo. Add all the ingredients to a medium bowl and toss to combine. Taste and season with more salt as needed.
Assemble the tostadas. Spread about 2 tablespoons of smashed avocado on each tostada shell. Add the shrimp and top with some mango pico de gallo serve with lime wedges.