The Kentucky Fried Chicken (KFC) recipe is a trade secret, but the general method is:

Marinate chicken pieces in seasoned buttermilk (or a brine).
Coat them in a flour mixture with spices (commonly salt, pepper, paprika, garlic powder, onion powder, oregano, thyme, and other herbs).
Double-dip by returning chicken to buttermilk, then flour again for a crispy crust.
Deep-fry in hot oil until golden brown and fully cooked inside.