Picture from thesartorialistRalph Lauren
A peacoat can be a great element for fall. A peacoat which usually comes in navy is a wool jacket. It can look great on most people. Pete Doherty and Brad Pitt wear them often(all the more reason to get them). Ralph Lauren makes good ones and I bet they can be found in some vintage stores. Just make sure you dont wear a blazer or a suit jacket under it.
Picture 1. The Sartorialist
Picture 2.Ralph Lauren