I am a retired elementary teacher who has two grown daughters and twin 13-year-old daughters. I have dealt with therapists for one of the twins for the past two years, and the most important thing I learned was that the anger that my ADHD child shows is not at me. I took every disrespectful word she said and tried to be a strict disciplinarian, which escalated things every time! Once I realized that her anger was at herself, I was able to step back and take a deep breath.
I am working on a master's degree in therapy (I want to work with abused children) and one of the suggestions I ran across truly helped. Choose a time when things are calm and tell the child(ren) that there are consequences for certain behaviors. The behavior that drove me nuts was when my daughter screamed at me in frustration. During a calm time, I said, "Screaming at me is disrespectful. When you scream at me, you need to hand me your phone, because that is the consequence." Days go by. Of course, she yells, I hold out my hand, she gives me the phone and tells me that she doesn't care. I stay calm (for a change) and put the phone away. I noticed that the screaming only happened once a week, then twice, now rarely. I truly think she has to weigh whether taking out her frustration on me is worth losing the phone.
Believe me, I know there are no easy answers. What works for one may not work with another! Experimenting is what parents do! I hope that my suggestion helps someone think of a consequence that works for their family!