To review your own games is excellent training. I like to look back at old games to get a better understanding of my improvement. Recently, I started to create a “Top 5 list” of all my OTB (“Over-the-Board”) games. I think such a list might be useful as a measure of your improvement. How? Well, one idea is to set goals such as: “At least one of my next ten games should make it into my Top 5 List”
Rating Improvement is of course a simply measure of improvement but the thing is that you can play the best chess of your life without winning a single game! The Top 5 List does not necessarily consist of won games.
Please note that making in into the Top 5 List is quite demanding if you have played a lot of games. A simple but crude estimate of the chance for a single game to make it into the list is “5/N”, where N = the total number of your games from where the Top 5 is created