Pat the turkey breast dry
Season with salt, pepper, garlic powder, onion powder, and herbs
Place sliced onion, celery, or carrots in the bottom of the crock pot if desired
Add a small amount of broth or water to the crock pot
Place the turkey breast in the crock pot, skin side up if applicable
Cover and cook on low until the turkey reaches 165°F in the thickest part
Cook on low for about 5 to 7 hours for a boneless turkey breast
Cook on low for about 6 to 8 hours for a bone-in turkey breast
Avoid overcooking by checking the temperature near the end
Remove the turkey breast and let it rest for 10 to 15 minutes
Slice and serve
Optional: use the cooking liquid to make gravy