Clean the shrimp and set aside. Combine the cumin, garlic powder, onion powder, paprika, chili powder, oregano, and salt. Combine the shrimp and the spices, toss until the shrimp is well coated. Let the shrimp rest while you prepare the avocado sauce.
For the Pico de gallo, combine the tomato, onion, peppers, and garlic, mix well. Add the lime juice and mix. Season with salt to taste. (The vegetables can be chopped the day before).
For the avocado sauce combine the avocado, sour cream, lime juice, cumin, garlic powder and onion powder in a mini food processor. Process until the ingredients are well mixed and creamy. Season with salt to taste.
Let the shrimp rest for 5 to 10 minutes. Heat 2 tablespoons of olive oil in a skillet. Add the prepared shrimp, cooking about 3 to 4 minutes on each side or until the shrimp turn pink.
To assemble the tacos, divide the shrimp between the tortilla shells. Top with the Pico de gallo and drizzle the avocado sauce over the Pico de gallo. Serve