I have been making monthly playlists for the past 4 and a half years, I do not skip months. They have been the most consistent tracking of my life over this time. There are a few rules, no full albums can be added and no songs can be repeated from past playlists. They range from 10 to 30 songs. I can tell how I was doing based on the number of songs and how congealed the musical narrative is. At this point they are habit, I make them to listen to during each month but I also make them to look back on. Producing a nostalgia for each month of each year. There are no overarching themes and these playlists decentralize my music taste, the yearly review lacks month to month consistency.