For particularly important decisions, consider contemplating them at different times, if you can. Think about one thing Monday morning, then Wednesday afternoon, then Saturday evening, going only to the point of getting an overall feel for an answer, and not to the point of really making a solid conclusion.
This seems congruent with the folk idea of “sleeping on” difficult or particularly important decisions rather than coming to a decision on the spot, and with the legal practice of having “cooling off periods” after a purchase is made or a contract is signed, during which one party can void the agreement.
This works for any shirt, jacket, or coat. In addition to the benefit you cite, it also make the garment hang more naturally on your body as you move your arms, since the sleeve is designed to be able move with your arms on the assumption that the cap of the sleeve is aligned with the top of your shoulder.
The test I usually do is to try on the garment and raise my arm without moving my shoulder. The spot where my arm starts moving should be at or just below the shoulder seam.