For a mocktail version, replace the tequila with a splash of blackberry sparkling water or a touch more lime juice. Adjust the simple syrup to your desired level of sweetness, depending on the tartness of the blackberries and lime. Experiment with different herbs! Mint or sage also pair beautifully with blackberries. Chill your cocktail glass in the freezer for a few minutes before serving for an extra frosty experience.