Viva Villa #2

2 oz tequila
1 oz lime juice
1 tsp lemon juice
2 tsp superfine sugar

Rub the rim of a cocktail glass with a lime wedge, and dip into sugar in a saucer or flat bowl; discard lime. Pour the tequila and juices into a cocktail shaker half-filled with ice cubes. Shake and strain into a cocktail glass, and serve.