​(Thanks Carl for raising this point)

I keep my Master List in OneNote. The tasks are linked to Outlook, so I can mark them completed in Outlook or OneNote. Also, I don’t delete my completed tasks, instead, I keep them on another page that I call “Completed Tasks” for reference. I move the completed tasks from the Master List to the Completed Tasks list manually as I was not able to find a way to move them automatically when they are marked completed. Even though I move the tasks manually, I still do it quite efficiently as demonstrated in the 2 min video below.