I also make an index as I go of the scripture passages I've written about with several keywords that point to the theme of the reflection. One fun side-benefit is that at the end of the year I can collect all of the keywords and display them in a Wordle where the most commonly used words show us in larger font size. The three images attached show what my devotional keywords were in 2015. The first one below uses all the words, the second just the 20 most common words, and the one above has the top 5 words by frequency.
(You'll notice that my most common keyword this year was "pipe." No, I've not been moonlighting as a plumber, "pipe" is just my personal shorthand for a core metaphor for faith and life. Briefly: to be human is to be like an L-shaped pipe, connected to God at the top, with love, joy, peace, forgiveness and all good things flowing *down* into us from God and *out* from us to bless our neighbors.)
I wanted to share this with you to encourage you in your own devotional life. (New Years... fresh starts... resolutions and all that.) First of all, of course, just to spend some intentional time each day with the Lord. And in addition, I highly recommend some kind of writing practice that lets you see your faith life over time and find good words again at a later date - for yourself or for others!
And while you're at it... and annual spiritual "year in review" is a pretty good practice too.