I cut the watermelon into 30 mm cubes and used 3 pieces to the shaker including all ingredients. Then meddled followed by a 30 second shake. Just like eating the fruit. Good very tasty, but I’m missing a cocktail taste. I tried the watermelon martini as prescribed but found it a bit tart. And slightly artificial. I’m thinking some muddled fruit in the watermelon martini will be trick yo an exceptionally fine cocktail.