1920s Mens Sweaters came in a variety of styles to go with each weight. The heavy Shaker shawl collar sweater with thick waistband and cuff ribbing was a favorite throughout the decade. College men adopted it wearing college colors and letters on the front pockets. http://www.vintagedancer.com/1920s/1920s-mens-sweaters/
Men (at least the highly fashionable ones) wore many accessories in the 1920s. Notice the different types of hats (here we see fedoras, straw boaters, and Newsboy hats). Canes were popular accessories as well as small rings, tie pins, and collar pins.