This seems obvious, but if you are working with a blank journal it is easy to forget. Granted, there are sophisticated mood apps out there that do most of the work. See Tech Cocktail’s list of the best habit and mood apps, as well as Time.com’s piece, Apps for Mastering Your Mood. But if you decide to go the old-fashioned way, remember to include the date. Put the day of the week, as well: Sunday, Monday, Tuesday, etc.