I found it wasn't the rules themselves that I struggled with, it was exploring my motivation. Before I told my daughter the boundaries, I had to work through them in my head to be sure the rules were about what was saving my sanity and establishing a peaceful home, not about trying to control her use or her recovery. So when I established a curfew, I adjusted that to say if she wasn't going to be home, she needed to call or text before the curfew to tell me she was staying elsewhere. I would not ask where - like Ann, the curfew was about my ability to sleep and not worry. Requiring her to be in every night for me would have been more about checking to make sure she was clean - which was crazy making.
Respect was huge, and responsibility for her own stuff, including bills, getting herself up, getting to work, OP, etc. I did not establish rules regarding contribution to the household (cleaning, cooking, etc) because I found I had resentments if it wasn't done in my time frame and my way. That was stuff I needed to work on myself, so just making it clear that I was not responsible for any of her "stuff" worked well for me. If she didn't deal with it, that was her problem, not mine and I had to focus on me to make sure I didn't make it my problem - which included nagging, giving unsolicited advice, etc. That one is a good boundary for any adult child, IMO - whether an addict or not. Makes for a much better relationship and gives them room to shine on their own.
What are some of the things that are creating the most stress for you? I think if you focus on them and what would help relieve that stress without trying to control his actions, it may be helpful. Hugs...I know it is not easy staying outside of the drama when you are living with addiction in your household.