Blood orange juice
Coarse sea salt
Pour blood orange juice, tequila, lime juice, orange liqueur and simple syrup in a cocktail shaker with a handful of ice.
Put the top on the shaker and shake for about 15-30 seconds until the cocktail shaker is chilled and frosty.
Fill the serving glass with ice and rim with coarse sea salt if desired. Strain the blood orange margarita into the glass.