Place the blackberries and lemon juice in a cup and muddle until berries are broken down. Mix in about 5 teaspoon of the simple syrup into the mashed berries. If your prefer a sweeter drink add an additional 1-2 teaspoons of syrup to your drink.
Next, mix in gin and fill the glass with ice. Top drink off with about 3 oz of water and gently mix everything with a spoon. Garish with mint and enjoy!
