One of the things I've gotten tremendous amounts of mileage out of it is tracking my time, habits, and life each day.
To put it simply - I now realize it's impossible to understand how your life is going without some careful observation. There's a lot of time each day, and knowing where that time goes, what you ate, what you did and didn't do... it's almost impossible to get a good picture of your life without some kind of measuring.
I'm going to you my newest tracking template, and then I'll give some analysis. Before I start though, I'd like to share a quote -
“A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over, beginning with a working simple system.” -John Gall
Thus, if you want to track your time, please do not attempt to track 20 things at once, because it's unlikely to work. I started very simply, as I described in "The Evolution of My Time/Habit/Life Tracking" - I'd recommend you read that post if you want to do something like this.