Make 4-oz of blood orange simple syrup by combining the sugar and blood orange juice in a small sauce pan; simmer over low heat until thick and syrupy. Allow to cool.

Add the above made syrup, tequila, triple sec and sour mix to a pitcher and stir. Pour 6-oz amounts into a cocktail shaker half-filled with ice cubes and shake well. Pour each amount over ice in a margarita glass; garnish as desired, and serve.