If chicken is not pre-brined, dissolve 1/4 cup kosher salt in 5-6 cups lukewarm water, cover chicken, and refrigerate 20 minutes to 6 hours.
Preheat oven to 450°F.
Remove chicken from brine or package and pat dry thoroughly with paper towels.
Place chicken in a large bowl and add avocado oil, kosher salt, pepper, garlic powder, smoked paprika, onion powder, and oregano.
Rub the oil and spices into the chicken breasts evenly by hand or with a spoon.
Arrange chicken breasts on a baking sheet in a single layer.
Bake chicken until internal temperature reaches 165°F: 12-15 minutes for small breasts, 15-20 minutes for medium, 20-22 minutes for large.
Optional: broil for a few minutes at the end to achieve browned, crispy tops.
Remove chicken from oven and let rest at least 5 minutes before slicing or shredding.