I have taken apart all the Hard Yakka pants I bought from Savers. Each side yields 4 long pieces, I have taken off the buttons and zips for use later. Each 1/4 of the legs makes two 4 inch wide strips and two 2 1/4 inch strips. This makes a total of 3 bag tops or in other words, 12 bag tops per pair of pants. I have 17 pairs of these.
Each pant leg strips.
Put into a laundry bag.
I have jeans that I will also do this too. I have enough hard wearing fabric for plenty of laundry bags this year.