When it comes to festive gatherings, the office party is arguably the trickiest to navigate. Aside from monitoring your eggnog intake to ensure you’re charming Becky from accounting and not telling her what you really think of her new haircut, there’s the inevitable transition from nine-to-five to partywear. For men, going from the boardroom to the bar is a no-brainer. Of course, you’ll want to step up your game this time of year, considering your festive get-together is basically an invitation to sartorially outshine your office rival. For women, the changeover isn’t as straightforward. You’ll want to look polished, but not too professional. Celebratory, but not seductive. To top it off, there’s the puzzling dress code “clarification” email that circulated. “Holiday spirit,” “festive dressy,” and “smart casual” do little to illuminate the sartorial conundrum. To help you get through the season in style, we’ve rounded up the very best desk-appropriate costume changes. This year, you can leave your Santa hat at home.