I have a group of... house spirits, I guess you could say. They help protect me and my space. Each is housed in a core object, and some of the oldest are more than ten years old. I don't have control over it, really. If there's a name for the precise process I use, I couldn't tell you what it is, but it comes out of my chaos magic practice and is similar to the creation of an egregore. Each has their own personality and is very much an independent spirit after some time.
A few days ago, one of the oldest ones, Faith, broke. I was pretty heartbroken when I realized what had happened. I've had figures go away by disappearing before, but it's been a long time since I remember one breaking. The last time it happened, I thanked the spirit for her help and gave her offerings to send her on her way.
This time, she didn't want to leave. She's been with me for so long, I suppose it's not too surprising, but it caught me off guard. She asked if she could have a new "home" instead. I was reminded of Anne, who has several ball-jointed dolls with life of their own, and suggested to Faith that she might like one of the dolls I've collected as her new "home."
Faith accepted and I placed the figures carefully before Mara, as she is the goddess of the home, and so all of our household spirits are in her care and service. With her blessing, it was successful and Faith was able to settle into her new core object.
There's a lot of discussion about plastic and the inherent magical qualities of different materials. Plastic has never given me too much trouble, though. I'm sure it's one of the many things that vary from one magician to the next.
In general I find that what people tell me should work and what actually works can vary. I just experiment for myself and take note of what works and what doesn't. If this hadn't succeeded, Faith and I would have tried something else. The key is always to figure out what works, and if possible, why.