Preheat your grill or a grill pan over medium-high heat.

In a small bowl, mix together the olive oil, chili powder, cumin, garlic powder, onion powder, salt, and black pepper. Rub this mixture all over the skirt steak.

Grill the steak for about 4-5 minutes on each side for medium-rare, or until it reaches your desired doneness. Remove from the grill and let it rest for 5 minutes before slicing.

While the steak is resting, prepare the avocado salsa by combining the diced avocado, cherry tomatoes, red onion, cilantro, and lime juice in a bowl. Gently mix to combine.

Warm the corn tortillas on the grill for about 30 seconds on each side, or until pliable.

Slice the rested steak against the grain into thin strips.

Assemble the tacos by placing a few slices of steak on each tortilla and topping with the avocado salsa.