I don't know if mine ever wear out. I just tend to lose one on accasion and that seems to get the job done on changing. That being said, if the ball is scuffed or marked, it goes into the shag bag and I use them to warm up on the range and for chipping…
I don't like to pick a general area while practicing. I like to pick a line and a distance and hit the dot. I usually practice at the range for a few hours here's my routine.
10 balls each for warm up, Pick a line and not worrying about distance…