While colors and binders can be fairly easily reproduced by following step-by-step instructions or recipes, drawing and painting are much more subtle matters.
To achieve excellence in drawing and painting, Renaissance artists dived deeply into the study of anatomy, perspective, proportions and harmony of forms, mechanics of the body and motions of the soul.
On the practical side, learning from great artists of the past, combined to studies from the nature was and remains today the main path to mastery in figurative arts.
The young man should first learn perspective, then the proportions of all things, next, he should work after a good master so that he becomes accustomed to beautiful forms ; next, after nature, to confirm the principles he has learned ; he should then study the works of various masters for some time ; and finally he should learn to apply and put into practice his arts.
Leonardo on art and the artist by Leonardo, da Vinci, 1452-1519, Dover Publications