Bill Tindall, E.Tn.
Knob installation is the last step. It has to be right for there is no way to repair a misplace knob and not have the errant hole become the focal point of the appearance.
Knobs have been turned, carved, and now it is time to position them on the case. If there is a formula for where knobs go I have not been successful finding it. So, I get someone to move the knobs around the case by hand until they look right. Then I paste them on with double sided tape and live with it for a while as I walk around the shop doing other stuff. If after a day they look to be in the right place they get installed.