One tip I would give you is to use a rotary cutter that requires pressure for the blade to be exposed and cannot be left in the open position. I believe Dritz brand is one of those type. No button to keep blade open as it automatically retracts when pressure is lifted. Also might consider those rulers with the raised edge on them. Can't remember what brand but they have an acrylic lip on one side. Or perhaps one of those suction handles so their hands are touching the ruler itself but just the handles. And of course supervision at all times is a must.