Rinse the shrimp under cold water and pat dry.
In a bowl, toss shrimp with chili powder, cumin, salt, and pepper.
Heat olive oil in a skillet over medium heat.
Add the seasoned shrimp to the skillet and cook for about 2-3 minutes on each side until pink and opaque.
Warm the corn tortillas in a separate pan or microwave.
Spread mashed avocado on each tortilla.
Top with cooked shrimp.
Add diced tomatoes and chopped cilantro on top.
Squeeze fresh lime juice over the tacos.
Serve immediately with lime wedges on the side.