I agreed with your statement about practicing with about not hitting the same iron over & over. Normally, I'll change up my clubs from odd to even on the the different days at the range, i.e. Driver, Utility, 5, 7, 9, GW or Driver, Fairway, 6, 8, W, SW. This leaves my LW & putter on the practice greens every day at the range. On the driving range, if I get 30 balls, then I hit 5 with club...60 balls, then I hit 10 with each club.