In a large saucepan, combine the water and sugar. Stir over medium heat until the sugar dissolves. Bring to a boil, then remove the syrup from the heat, and allow it to cool.
Once cooled, mix the syrup with the lemon juice and lime juice. Chill once more.
Store covered in the refrigerator for up to one week.
Video
Notes
To mix up into a classic margarita I do about 3 ounces of margarita mix, 2 ounces of silver tequila, and 1 ounce triple sec. Shake it up with ice and serve serve in a salt rimmed glass with a wedge of fresh lime. Voila!The recipe makes 8 cups. Based on the serving size listed about this should make about 20 margaritas.