I have been experimenting to develop an accurate method before I drill some holes on 4 walnut table legs. The 1/2" Forstner bit I was using has disappeared. I have looked high and low for it multiple times over the course of several days. It was good quality bit I bought some years ago. So, I finally broke down and bought a cheaper replacement, a Diablo, at HD. It's sitting on the dining room table ready to be taken to the shop. I am sure as soon as I take it to the shop and cut it out of it's plasticized container and use it, I will find the original! This method always seem to work for me!