If you enjoy a salted glass, prepare the rim by rubbing a lime wedge along the rim. Dip the glass in tequila salt, and set aside.
Make the cocktail
Fill a cocktail shaker with ice and add tequila, Cointreau, lime juice, and simple syrup (if using). Shake until the sides are fully frosted.
Pour
Fill the prepared glass with fresh ice and strain the mixture over the ice. Top the cocktail with champagne.
Garnish
Garnish with a wedge of lime.
Notes
Make a pitcher (serves 8) with 1 cup fresh lime juice, 1 cup tequila, 1 cup Cointreau or triple sec, ¼ cup simple syrup (optional) and 1 bottle of champagne. Mix all the ingredients, except the champagne in a pitcher and refrigerate. Pour a little less than ¼ cup of the mixture over ice and top with champagne