There is a catch to using strips; If you are in control of what you eat every meal, you generally get the same result every time. So, I know what happens what I eat, how much I eat, when I eat (after a week of trial and measuring bg) I only use one strip at nights, before bed. If I overeat for some reason, I sometimes use an extra strip during the day. Regular eating habits help a lot on using less strips a month.
Dont forget that overeating carbs and sugary food will cause your bg get stable in 2-4 days, quickest.
Every metabolism is going to probably act different, not that stable and predictible like mine, but this way works for me totally great.