An observation I have made with students is the difference in shading cuts between those who hold the handpiece the traditional way with the thumb on the side of the graver versus those who place their index finger on the top of the graver. The finger-on-top users can sometimes cause too much downward pressure which can make it extremely difficult to achieve the micro-thin startup to shading lines. Keep this in mind if you're struggling with shading and not getting a super thin taper at startup.