My son has ADHD too. It can be exhausting having to remind them every day to do things like brush teeth or take a bath. I bought a magnet board / chore chart that lists the things he has to do everyday and that does help. He gets a reward at the end of the week if he's done the activity every day.

I've tried lots of different reward systems and what works probably depends on the age of the kid and the kid's interests and likes. It took me a few tries to find one that motivated my son. He's gotten very good at his self care routine as a result.

We are still working on homework routines / organization, though.