For example, when I wanted to get in better shape, I started calorie counting (in addition to exercising more, etc). I entered everything I ate into a website. This helped me become aware of what I was consuming- which can be quite deceiving.
Once I got a better handle on what foods were "dangerous" (not just bad for me, but which I ate in large quantities), I stopped calorie counting, but I'm maintaining my shape. I may go back to calorie counting every once in a while to see if anything's changed, but just that initial investment of time paid off quite well.
"Make Your Own Mobile Self Tracker with Google Docs"
Quantified Self Meetup Groups:
Not too long ago I felt I was getting to the end of the month having spent all my money and didn't have much to show for it. On-line receipts and a review of bank statements allowed me to account for some but plenty of it had been cash or purchases at places I spent money regularly enough that tracking it from a bank statement wasn't possible.
So I started logging everything I spent to find out what the money was being spent on.
Three months later I'm none the wiser where the money was going but I do tend to have £150 more left and the end of the month than I used to. Knowing that I'm going to have to write it down and account for it to myself has just stopped me spending money on things I'm not that fussed about.