Bring sugar and water to a boil, stirring until the sugar dissolves. Let cool. Makes 2 cups.
Spread the salt on a small plate. Moisten the rim of a glass with the lime wedge; turn the glass in the salt to coat. Fill the glass with ice.
Fill a cocktail shaker halfway with ice; add the lime juice, tequila, triple sec and Rich Simple Syrup. Cover; shake vigorously until cold, about 15 seconds. Strain into the salt-rimmed glass and toss in the lime wedge.