Soak chicken overnight (at least 8 hours and up to two days) in buttermilk with onions, herbs, paprika, and cayenne pepper. (Regarding the use of buttermilk, my mother has had good results from soaking chicken in plain yogurt instead of buttermilk.)

Drain in colander, leaving some herbs on chicken. In a large paper or plastic (sturdy) bag, mix flour with seasonings. Meanwhile, heat 2 cups oil in a large, heavy-bottomed skillet (cast iron, stainless steel, or anodized aluminum - something that can take the heat) on medium high heat until a pinch of flour starts to sizzle when dropped in the hot oil (but not so hot that the pan is smoking). Remember when working with hot oil, always have a pan lid close by.

Place chicken pieces in bag with flour and shake until thoroughly coated. Add chicken to hot pan and fry on 1 side for 12-15 minutes, until golden brown, and then use tongs to turn the pieces over and fry for another 10-12 minutes, again until golden brown. 

Be careful to keep the oil hot enough to fry the chicken, but not so high as it burns the chicken. To do this on our electric stove we have to alternate the settings between high to medium high several times while we are cooking.

Use tongs to remove chicken from pan. Place on a rack over a cookie sheet or broiling pan for the excess oil to drain. Add more salt and pepper to taste.