In the zone system scale, zone 0 represents maximum black and zone X represent pure white. There is no discernible textural detail in those areas. Zone V represents 18% gray, zone lll good shadow texture, and zone Vlll good highlight texture. All meters will give the f-stop and shutter speed combinations to produce a zone V density at what ever they are pointed at. (If you measure only the bright white fabric in a wedding gown or a black cat in a coal bin and set your exposure accordingly, both subjects will be rendered as the same 18% gray in the resulting 2 pictures) So to produce the true tonal value of the cat and see good textural detail, I would place my metered value of the cat on zone lll, because zone lll represents good visible shadow detail. The cat then must be underexposed by 2 stops from what the meter recommends, so that area will record as a zone lll value in the print. [note: a spot meter is best because you can meter important parts of the scene separately from a distance]
The principle of "expose for the shadows and develop for the highlights" is true as altered development times will enable you to compact or expand the highlight densities of any subject into the printable range of photographic paper without changing the shadow densities.
To begin, you would pre-visualize the scene in terms of tonal values and decide the darkest area of tone where you want to see some detail. You then meter those areas in the scene. In this church interior for example, using the spot meter in a Leica M5, I selected and metered the dark areas on the front of the altar and front of the small pipe organ, and placed them on zone lll to show textural detail in the shadows. That determined my exposure.