My process is similar to Nonie's, except I use diluted shampoo. My shampoo is in a color application bottle, and after thoroughly wetting my hair and scalp I apply the shampoo to the scalp and gently massage, then I rinse allowing the suds to run through the twists while gently squeezing the length in a downward motion.
Then I squeeze out excess water and apply my conditioner, squishing it through the twists, again in a downward motion (if that makes sense), put on a plastic cap and finish my shower. Remove cap and rinse for at least three minutes under the showerhead while squeezing the length. If I'm doing an ACV rinse, I do it after my conditioner, and apply it with a squeeze bottle, then rinse. Wrap hair in a tshirt or micro fiber turban and after the drippies are gone, apply shea butter and oil to hair and let dry completely.
I don't really get that much frizz to be honest, and I keep my twists in for at least two weeks before redoing them and I always wash in twists-never loose.