The always dapper gents at British Esquire have plenty of rules on what men shouldn't wear: "These include (but are in no way restricted to) functional trousers which zip off at the knee; dirty white deep V-neck T-Shirts ... and, up until recently, sandals." But, as you may've heard, the open toe look is having a moment with stylish men. From Birkenstocks and dressier leather styles to technical sandals and flip-flops, they offer some rules on wearing them and even suggest solid options to consider buying.