We’re not going to lie—we really didn’t see the rise of the sweater vest coming. This wonderfully nerdy staple, beloved by such comedic (but not fashion) icons as Doug Funnie and Chandler Bing has been steadily growing in popularity since the beginning of the year, or even earlier, and is only becoming more ubiquitous now that fall has officially arrived. If you’ve found yourself wondering how to style a sweater vest and not look like an old college history professor (no offense to them), you’re not the only one. We’ve rounded up ten incredibly stylish, fashion-forward ways to rock this classic preppy knit—and one look to avoid—that are sure to impress even your most sartorially advanced friends. Here’s exactly how to style a sweater vest with aplomb in 2021.