A comfortable seam is care placed where nobody is meant to look.

Some quality is only ever experienced by the person using the thing. The inside of a garment is never photographed and sits against the skin for hours, which makes it a fair test of whether the maker was thinking about wearing or about selling. Care hidden from view is care that had no audience to earn. That tends to be the most reliable kind.

Look for the unseen parts of what you buy and what you make: the lining, the underside, the join nobody will inspect. Then do one job this week to a standard no one will ever notice.