In a large bowl, combine the shrimp, olive oil, lime juice, lime zest, garlic, cumin, chili powder, salt, and pepper. Toss to coat the shrimp evenly. Let marinate for 15-20 minutes.
Heat a large skillet over medium-high heat. Add the marinated shrimp and cook for 2-3 minutes on each side, or until they are pink and opaque. Remove from heat.
While the shrimp is cooking, warm the corn tortillas in a separate skillet or microwave until pliable.
To assemble the tacos, place a few shrimp on each tortilla, then top with shredded cabbage, avocado slices, and chopped cilantro.
Serve with lime wedges on the side for squeezing over the tacos.