I started tracking my expenses about two years ago.
This was one of the best things I ever started. It showed me where I could save, and it has helped a lot.
I still track my expenses to this day. I use a google spreadsheet and write down what comes in and what goes out.
Shortly after starting this, I figured out that my two biggest costs were medical bills and groceries.
Not much I can do about that billion dollar medical scam, the bills need to be paid, but I've been able to adjust my grocery shopping habits, and I save a lot there.