Coaching for children under 12 will require a parent to be close by during the session. You may not need to sit in the room with your child for the duration of the session, but the strategies that need to be implemented must have the help of a parent, guardian, or family member.
This may also be required for some teenagers, depending on how well they can implement tasks on their own. Coaching children is very much family and/or parent coaching as well. I can help you with finding ways to implement tasks and strategies, but your child will need guidance from you to ensure skills are built over time.
My kids coaching sessions often involve some physical activity to help children with attention and focus. The sessions are interactive and include activities to build executive function skills that many children with ADHD struggle with.