The classic peacoat is a navy wool double-breasted coat with broad lapels, six buttons and vertical side slash pockets. It's a classic for a reason in that it never really goes out of style, but tinkering with the recipe can produce some interesting variants that should still stand the test of time. From left to right: Try a different colour [Reiss, $520]. Add a pattern [Andrew Marc, $225]. Do it as a knit instead of a weave [Suitsupply, $300].