FLYLady. I tried to follow her programme a few years ago but, getting her emails through the day to remind me to do a new task, I found it impossible. It seemed to be designed for people who had nothing to do but wait for her mails and it just didn’t suit someone with other things to do (like work, go out, see friends etc.)
However, there is some useful stuff in this video about how and where to start a decluttering journey. It’s common sense in many ways, but those of us with hoarded houses have to admit that we lack a certain amount of common sense in these areas!! Enjoy.