Cut a slice and wedge from one lime half; set wedge aside. Rub rim of glass with slice; dip rim into coarse salt. Juice remaining lime halves to get 1 ounce. In a cocktail shaker combine lime juice, tequila, and liqueur. Add ice cubes; cover and shake until very cold. Strain into a glass with additional ice. Garnish with lime wedge. Makes 1 serving.