1/4 teaspoon salt
1 1/2 fluid ounces vodka
5 fluid ounces grapefruit juice
1 cup ice
Sprinkle salt on a small plate or in a shallow bowl. Lightly wet the rim of a highball glass with a moistened paper towel. Dip the rim in salt to coat. Pour vodka and grapefruit juice into the prepared glass. Add ice and stir to combine.