Like they say, there is more than one way to skin a cat. I don't have that much experience coring, but I made these boards that help me visualize where the bottom will be and how thick the base of the bowl will be. I have found that I would rather start with the biggest bowl and make sure I have that one right. Then work down to the smallest one. I have also found if the blank is deep enough, you can get two large bowls by starting on the outside. If I had planned the shape better, (straighter the first inch or so) it would have worked out better. The two biggest would be closer to the same size.