1. Always trust your instincts. The first test is to make sure the material feels good to the touch. A quality dress shirt should be woven from 250 two-ply cotton and will therefore be stronger, softer and less sensitive to wrinkling. The design of the fabric should match where any two pieces of fabrics meet.
2. Also, make sure the shirt is single-needle stitched—more yarn is used, but seams are stronger. Inspect the seam running down the side of the shirt for smoothness and make sure it does not pucker.
3. The collar of a great fitting custom shirt should be firm and crisp. It should not be limp and under no circumstances it should have any wrinkles or bubbles. A well made custom shirt should have removable stays or built in stays for a crisp, firm look. The collar should be constructed in two pieces and hand turned.
4. A quality dress shirt should have split-yoke detailing. The yoke is cut in two and sewn up the middle rather than placed in as one piece.
5. Pay attention to the buttons: Mother-of-pearl is preferable to plastic. They should be sewn with a cross locked stitch to ensure your buttons stay firmly attached. Examine the shirt sleeve a couple of inches above the cuff for a gauntlet button that closes up the sleeve.