Yes, I use the counting principle in my day-to-day life.
I have used the counting principle to overcome to perform the following task in day to day life:
1 ) In order to schedule my school timings and study timetable choices I have used the counting principle.
2 ) I have 7 T-shirts and 5 pants in my wardrobe for daily wear. I use the counting principle to set up different combinations and decide a particular pair of shirt-pant combination for a day.
3 ) I have playing cards with me. On weekends when I play with my cards, I use the counting principle to decide which card is to be drawn first so as to win the game.