I have a simple system. For every “project” I’m involved in i make a new Google folder and at the top of it i make a notes doc. The document has a table at the top filled with pertinent information about the project, and then just below that I take notes for every day. Every day that I work on that project at least. Yesterdays notes get pushed below today’s notes and I just move forward like that. I just search Google docs for keywords and find them in my notes from days weeks or months ago. The nice thing about Google docs as I can take screen captures and just stuff them in the doc