For an autumn or winter wedding, guests coming in from the frosty weather need something to perk them up, as well as to heat their hands and bellies. A dessert barista, with his know-how and ingredients, can easily work some coffee alchemy and infuse the party with a hot, sweet buzz. Stock the coffee bar with fresh milk and cream, turbinado sugar and flavored syrups. You'll also need plenty of sweet treats like chocolate-dipped biscotti, gourmet cupcakes and madeleines. For an extra dose of warmth, you can even provide some coffee mixers like a nice bourbon, amaretto or dark crème de cacao to make the evening even cozier.