In a medium bowl, combine the chicken thighs, olive oil, chili powder, cumin, smoked paprika, garlic powder, salt, and black pepper. Toss until the chicken is evenly coated.
Heat a large skillet over medium-high heat. Add the seasoned chicken thighs and cook for 5-6 minutes per side, or until fully cooked and internal temperature reaches 165°F.
Transfer the cooked chicken to a cutting board and let it rest for 5 minutes. Use two forks to shred the chicken into bite-sized pieces.
Return the shredded chicken to the skillet and pour in the lime juice. Stir to combine and cook for 1-2 minutes, until the chicken is heated through and absorbs the lime flavor.
Warm the tortillas in a dry skillet or microwave until pliable, about 30 seconds.
Assemble the tacos by dividing the shredded chicken evenly among the warm tortillas. Top with shredded lettuce, diced tomatoes, chopped cilantro, and a dollop of sour cream.