Shoulders-
A well-fitted shoulder lies flat. The seam on top of the shoulder should be the same length as the bone under it, and should meet the sleeve of the suit right where your arm meets your shoulder.
If the seam that connects the sleeve to the jacket is hiked up along your shoulder bone, or dangling down on your upper bicep, the jacket is never going to sit properly. In these instances, you’ll see “ripple effects” that create lumps or wrinkles on the sleeve and the top of the jacket. If you can’t move your arms well, or if you cannot pinch just the jacket, it is too small. If the shoulder seam of the jacket is below your shoulder, or the sleeves run farther than 1/2 an inch past your wrist than the jacket is too big.