Place the chicken breasts into a slow cooker with at least 6-quart capacity, then pour in the chicken broth or water.
Sprinkle the salt, black pepper, garlic powder, and any other preferred seasonings over the chicken.
Cover the slow cooker and cook on the LOW setting for 4 to 6 hours until the chicken is fully cooked and easy to shred.
Remove the cooked chicken from the slow cooker and transfer to a cutting board or a large rimmed pan.
Shred the chicken finely using two forks, shredder claws, or a meat shredder tool.
Return the shredded chicken to the slow cooker and mix it well with the remaining juices.
Once cooled, store the chicken in an airtight container or zip-top bag in the fridge for up to 4 days, or freeze for up to 3 months.