Amputation danger…
Cut a sheet or two first before cutting a stack to verify accuracy of the cut. Remember which sheet is to the left or right of the blade so you know which way to adjust the cutter.
If you are cutting a sheet in half, you can fold it in half and mark the fold to know where to cut.
Clean hands thoroughly before handling paper, or else you will leave smudges. If the climate is hot and you are sweaty, hopefully you have an option to start the air conditioner.