A garment can look good on a hanger and still fall apart after a few washes if the stitching underneath is weak. Checking seam allowance, thread tension, and whether seams are overlocked or simply cut raw gives a quick sense of how long a piece will last.
Buttons and zippers deserve their own check — a button sewn with too few stitches, or a zipper that catches on the first pull, is one of the most common complaints in ready-to-wear. Testing a sample piece by hand before approving a full production run saves costly returns.
Finishing touches like hemming, collar shape, and whether the print or embroidery is aligned with the seams often separate a piece that looks premium from one that looks rushed, even when both use the same fabric.