When making copies I refer to a specific instrument. E.g. I have copied the «Ole Bull» violin from 1744 by Giuseppe Guarneri del Gesù several times.
To create an authentic look and sound I make my copies in the Cremonese manner («metodo classico cremonese»). Many stylistic details – e.g. the fluting of the arching or edge work – just happen the right way by using this method.