This one is typical of the old door liners.
I have elected to use 3 ply as it is reasonably light and better when it comes to water damage (I'll be using plastic sheet under it as well).
First I acertained that the door liners on left and right sides of the car were mirror images of one another. Then I choose the best one, stripped off the vinyl and traced it onto my 3 ply - including the holes for handles, window winders, armrests and mounting clips. Then I firmly applied masking tape over the lines where I was going to use my old trusty jigsaw.
Once cut, removing the masking tape shows hardly any splintering.
I am lucky enough to have inherited (really) some hole punches. The door clips and armrests use a 1/2" hole. The only problem I had was on one panel near the corner it split the whole corner out. Some woodglue fixed that.
I had to bash out over 100 holes.
I now have four stamped 3 ply panels. Next comes a test fit (just to be sure the armrest, winder and door opener holes are correct) then the fabric covering.