To serve the perfect mixed berry spritz, start by gathering your ingredients: a handful of fresh mixed berries (such as strawberries, blueberries, raspberries), a bottle of sparkling water, a quality berry-flavored syrup or liqueur, a few ice cubes, and a sprig of fresh mint for garnish. Begin by muddling the berries in a glass to release their juices and flavors. Add ice cubes to the glass, then pour in a generous splash of berry syrup or liqueur, depending on your desired sweetness. Top it off with chilled sparkling water, gently stir to combine, and garnish with a fresh mint sprig. Serve your refreshing mixed berry spritz immediately, and enjoy the delightful blend of sweet berries and fizzy bubbles.