how did you go NC?

I'm considering going NC, or at least, setting severe boundaries so that I can be mostly NC. (I'm in a period of NC right now. But I do intend to reply to her once I'm able to.) What did you tell your parent? How did you set the boundaries? I would love to read other people's examples. I am trying to have compassion for this woman who raised me, but it is so so hard.