Experience is still the best teacher!
I can understand how it can be hard for a "newbie" to "know" what is considered "good" from just reading a book or using the internet.
With the cost of fabric being comparatively high, one would want to avoid costly mistakes when selecting fabrics for a project.
There just is no substitute for handling fabric to learn how it will behave. (Which, for me, includes washing and drying it - before cutting it)