For a shortcut, substitute frozen limeade concentrate for the lime juice and sugar. Like it slushy? Add ice and whiz the mixture in a blender. Make any size batch of this recipe and all the variations by simply multiplying the ingredient measurements by the desired number of servings. For larger batches, stir together all ingredients in a pitcher until powdered sugar is dissolved. Chill and serve over ice. For a sweeter drink, use 1/2 cup powdered sugar instead of 1/3 cup.