Easy way to make shingles

Making shingles cannot get any easier now that I have rediscovered that tool.
My father gave me that tool a couple of years ago (I don't know how it is called though, sorry), but I kind of forgot about it until today. I found it at the bottom of my tool box (one of my toll boxes should I say). Goodness! It works so well! I am using veneer ribbons (not sure that how that is called...sorry again). I cut pieces of 12inches and made a mark every half inch so I know where to cut.
I still am not done making the bricks on my retro dollhouse...and should probably not work on the shingles until the bricks are done, but I wanted to try that "new technique" RIGHT NOW! lol