Her official advice from someone using this hole saw on a drill for the first time: - It makes a very clean hole but wastes as large a circle as it can on a drill be stiff. Take a little at a time. It resonates and makes you scream LOUD (no, really. LOUD). USE HEADPHONES. USE A SPRING. I thought that was stupid and tried my first haircut without it. After that I spent 15 minutes hollowing out a wooden disk - DO NOT TOUCH THE FEATHER. It gets stuck in the wood disc after cutting. Touch it and it will instantly give you second degree burns. Don't ask me how I know that. Please.