Most of us have a better forehand than backhand usually and you can break the court down so easily and simple to use your stength more often to win many more points. Its a great guideline to improving point play and decreasing the chances of low percentage shots creating great self discipline.
You split the court into 3 sections and talking from a right handed perspective -
P1 - Hit forehands from here cross court
P2 - Hit forehands from here and change direction and go down the line to the backhand
P3 - Hit your backhand from here cross court (if you hit a forehand you will find your-self in the doubles lines and longer to recover back in the court)
So anytime your opponent hits into P1 or P3 hit back crosscourt because if you hit down the line from those places you will find you leave too much court open on the other side.
Anytime it lands in P2 much easier to change direction and go down the line to there backhand as you can push your opponent past the doubles lines and off the court and they will have a longer time to recover.
Have fun on the court and i'm sure you will find this system quite easy and helpful to win more points.