I do exactly the second part of this. Nobody is going to read what I write, so I just write about what I did, how I did it and what I was thinking when I did it. Not everything has to be written as a perfectly cited essay, but often just noting down what you did can be helpful in the long run. Sometimes I've thought of something, remembered that I did something useful and related in the past and dug out an old article to consult my previous thoughts