Place chicken in the slow cooker and sprinkle with seasoning packets. Pour salsa over and around the chicken. Cover and cook on high for 3 1/2-4 1/2 hours or on low for 5-6 hours, until chicken shreds easily and is no longer pink.
Shred chicken in the slow cooker and stir to combine. Cover and cook an additional 20-30 minutes.
Assemble tacos in taco shells with desired toppings. Serve immediately.
I usually make a double batch and use the full packets of seasoning mix. Great for tacos, burritos, salads and more!