Make the Creamy Sauce: In a small bowl, combine sour cream, mayonnaise, juice of 1/2 lime, 1 tbsp chopped cilantro, garlic powder, and a pinch of salt. Stir until smooth. Cover and refrigerate until ready to serve.

Prep the Shrimp: Pat the shrimp completely dry with paper towels. In a medium bowl, toss the shrimp with chili powder, cumin, salt, and pepper until evenly coated.

Cook the Garlic: Heat olive oil in a large skillet over medium-high heat until shimmering. Add the minced garlic and cook for 30 seconds until fragrant, being careful not to burn it.

Sear the Shrimp: Add the shrimp to the skillet in a single layer. Cook for 1-2 minutes per side, until pink, opaque, and curled into a 'C' shape. Do not overcrowd the pan; cook in batches if necessary.

Finish with Lime and Cilantro: Remove the skillet from the heat. Add the juice of 1 large lime and the 1/4 cup of chopped cilantro, tossing to coat the shrimp.

Warm Tortillas: Warm the tortillas in a dry skillet, over a gas flame, or in the microwave until soft and pliable.

Assemble: Fill each warm tortilla with a few pieces of shrimp. Drizzle with the creamy sauce and add your favorite toppings. Serve immediately.