Tad Spurgeon said this quote

“ This is the essence of Rembrandt's advice to Van Hoogstraten: the authentic craft develops naturally from one's own experience.So, it seems reasonable to suggest that the search should not be for the lost secrets, but for one's own practice. This is in fact easy, you start making things. At first they might not be perfect, but the information here should provide you with a running start. And, if you are cut out for this the learning curve will not be daunting, because you will realize that you are finally headed in the right direction: towards the living craft. ”