I’ll be honest, I’m 26 with ADHD and I still struggle with this constantly. I can’t speak on what works, but I can tell you what the biggest detriment for me was. For my entire life I was simply told to do things and never given a direct answer on HOW. When told to “clean my room,” I’d sit for hours stressing over where to start, and how to finish. How do you know when it’s clean enough? What if I work all day on it and it’s not good enough? I think what would have helped me the most is having someone walk me through the process a few times, and start the task with me. At all costs, avoid making your child feel embarrassed or ashamed about his mess. For me, those feelings led to an inability to ask for help when I got overwhelmed.