For an extra touch of elegance, garnish with a blood orange slice or a sprig of rosemary. Adjust the amount of sparkling water to your preferred level of fizziness. Experiment with different types of vodka to find your favorite flavor profile. Citrus-infused vodkas work particularly well. If you don't have blood oranges, regular oranges can be substituted, though the flavor will be slightly different. Best enjoyed immediately to preserve the fizz and chill.