Women have it easy with a simple non-white dress. For summer, a man’s traditional dark suit can be too warm and predictable. For a city wedding, choose a lightweight suit in gray, blue or a subtle pattern. Style it up with a pastel Oxford or poplin shirt. In the country, blazers and sport coats reign, paired with well-cut chinos. Seaside or resort? A tailored white shirt, colored chinos and a light-colored linen blazer. Keep everything understated and appropriate for the venue. And always be ready with a clever toast.