Most men in the USA let their shoulders on their suits make up for what genetics failed to do. But take a note from the Italians. They believe that the shoulder on a jacket should conform to the body of the wearer.
Behold...the Napoli Shoulder, Attached to the sleeve head the way a shirt sleeve would be attached to to the yoke of the shirt. The next time you visit your tailor to purchase a jacket inquire whether or not he can produce a Napoli shoulder. Just a "small" detail that makes a "big" difference.