If you enjoy a salted glass, prep the rim of your glass by rubbing a lime wedge along the rim. Dip in tequila salt, and set aside.
Shake:
Fill a cocktail shaker with ice and add tequila, Cointreau or Triple Sec, lime juice, lemon juice, and simple syrup. Shake until the sides are fully frosted.
Serve:
Pour, with the ice, into a highball or footed glass and garnish with a wedge of lemon, lime, or both.
Notes
Make this a longer cocktail by topping it a few ounces of club soda, sparkling water, or lemonade or limeade.
Make a pitcher by combining ¾ cup lime juice (about 6 limes), ¾ cup lemon juice (about 6 lemons), 1 ½ cups Cointreau or triple sec, 3 ½ cups silver tequila in a pitcher. Mix well, add lemon and lime slices in the pitcher, and refrigerate. Pour over ice.