In a cocktail shaker combine blueberries and fresh lime juice. If using frozen berries, let stand 5 minutes. Using a wooden spoon, muddle, or mash, the blueberries with the lime juice. Add tequila, simple syrup, triple sec, and ice. Cover with lid and shake.
¼ cup fresh or frozen blueberries, 2 tablespoons fresh lime juice, 1 ½ ounces good Silver Tequila, 1 ½ tablespoons simple syrup, ½ to 1 ounce Triple Sec, Ice