About 50 years ago, I developed a similar system. I handwrote my notes related to the planned article as they came. After having a few pages of them, I reviewed them. Then, I took a few color markers and put, let us say, red circles by notes that would go to the opening. Green squares were by the notes related to what I wanted to have in the following section. Blue triangles were for the next section, and so on. For longer texts, I would add numbers to keep track. With computers, it became easier to do.