First before anything soak the chicken in a bowl of water with 1 - 2 tbsp of salt for at least 1 hour. This gives the chicken a great flavor. I prefer to do this overnight.
Take your cut up chicken pieces and skin them if you prefer. Put the flour & cornstarch in a large bowl, dish, etc. Season the flour with chili powder, paprika, garlic salt and pepper to taste.
In a separate bowl whisk the egg and the milk together.
Dip chicken pieces in egg wash then, into the flour
Place the coated chicken on a cookie sheet or tray, and cover with a clean dish towel or waxed paper. Let the chicken sit for at least 30 minutes. This helps the breading adhere to the chicken and stay in place when frying.
Fill a large skillet (cast iron is best) about 1/3 to 1/2 full with vegetable oil. Heat until VERY hot about 375 degrees F.
Put in as many chicken pieces as the skillet can hold. Brown the chicken in HOT oil on both sides. When browned, reduce heat and cover skillet; let cook for 30 minutes (the chicken will be cooked through but not crispy).
Remove cover, raise heat again and continue to fry until crispy.
Drain the fried chicken on paper towels. You may have to fry in batches depending on the amount and size of your skillet. Keep finished chicken warm in the oven until it is all finished.