1/4 cup sugar (to rim glasses)
1 1/2 ounces vodka
1 ounce red grapefruit juice, plus strip of grapefruit peel for garnishing
1/2 ounce elderflower liqueur
1/4 ounce lemon juice
Spread sugar on small plate. Moisten rim of glass by running grapefruit wedge around outer edge. Roll moistened rim in sugar to coat.
Add vodka, grapefruit juice, liqueur, and lemon juice to cocktail shaker, then fill with ice. Shake until well chilled about 30 seconds. Double strain cocktail into prepared glass. Garnish with grapefruit peel.