Look inside the garment
The inside reveals seam finishes and how the lining is attached. Simple construction can be sturdy; complexity and quality are not automatic synonyms.
Check stress points
Gently check around pockets, buttons and side seams. Look for broken threads, opening stitches and thinning fabric without forcing the garment.
Check fastenings and linings
Test zips, hooks and buttons without pulling sharply. The lining should move with the garment rather than tug; a small repair differs from widespread damage.
Fabric weight and hand
Fabric should suit its purpose: a summer jacket has different needs from a coat. Feel and fold it gently, but do not infer durability from weight alone.
Quality as a whole
Consider material, cut, condition, comfort and repairability together. A well-made garment is also one that fits your life and that you want to wear.