How do I create effective boundaries between me and the addicted person that I love? To begin you have to understand what you are doing and what is it that you are trying to accomplish? Also you want to know when a boundary is effective?
So many family members live in a rigid world of automatic reactions to the addicted person in their lives and have no understanding of what they can do that is helpful. What they are doing doesn't seem to be working but they don't know what else to do. If they seek help they are told that it is important to take care of themselves and allow the addicted person to suffer the consequences of their behavior. These suggestions seem unnatural to many people. If someone you love is suffering you must help them, anything else seems selfish and cold. People feel they are not being a "good" wife, husband, parent, child or friend. This confusion is why it is so important to understand what you are doing and why you are doing it when creating boundaries.
It is true that an addicted person will not seek help until they experience a level of pain that breaks through their normal system of denial. It is also true that it is not the family's job to make the addicted person suffer and hope that this will make them go into treatment. This type of thinking is a recipe for frustration.
It is important for family members to be able to manage their expectations, and to understand that there is no perfect system for interacting with an addicted person. Creating boundaries means that you stop trying to manage someone else's life at the expense of your own.
Effective boundaries means that when an addicted person experiences a negative consequence because of their addiction you don't interfere to buffer the experience. You manage your expectations by understanding that this negative experience may not be the one that gets them into treatment but is necessary for them to experience and deal with because it is their life and they created this experience. You have issues to deal with in your own life that you have probably neglected in the past by coming to the addicted person's rescue.
You should always be experimenting with ways to live a normal life in spite of your loved ones addiction. You can start by experimenting with small stuff. I have had a number of mothers who have had their adult children wind up back home. The adult children don't pay rent, don't do chores but are using drugs/alcohol. The mothers do what many other mothers do, their kids laundry. The problem is that these kids are 23, 28, 34, or 46 years old. My first question to them is why are you doing their laundry? It seem that it was one of those automatic behaviors that is problematic when dealing with addiction. They thought it was just what a "good" mother did. I usually suggest they try an experiment and stop doing their adult kids laundry. Their laundry is their responsibility not yours. There are a variety of different types of small things like this such as cooking them dinner, buying them cigarettes, letting them use your car that you can decide that you don't want to do any longer. This is not punishment. This is about adults demonstrating responsibility for themselves.
Another aspect of creating effective boundaries is understanding that you cannot control their addiction but you can control your environment and how you decide to respond to your loved ones addiction. You start getting an idea that you are being successful at creating effective boundaries when you find yourself moving from rigid responses driven by fear and expectations to having a choice in how you want to respond in every situation.