On Craft

I came across the following:
‘In the fine arts, a master class is a small class where students and coaches
work together to support a high level of technical and creative excellence.
This book tries to capture the spirit of a master class while providing
coaching for readers who want to refine their skills as solvers of problems,
especially those problems dealing with mathematical inequalities.
The most important prerequisite for benefiting from this book is the
desire to master the craft of discovery and proof. ‘ – J.Michael Steele
Now I wonder if there is a finer example of Mathematics as craft, explained anywhere?