Here's a roughly scaled down version of the recipe I like:
Ingredients (Serves 6)
12 ounces silver tequila (about half of a 750-milliliter bottle)
5 ounces triple sec liqueur (1/2 cup plus 2 tablespoons)
4 ounces fresh lime juice (1/2 cup)
4 ounces fresh lemon juice (1/2 cup)
7 ounces simple syrup (3/4 cup plus 2 tablespoons; see note)
1 lime, cut into 8 wedges
Put all ingredients except lime wedges and salt in pitcher. Stir well.
Moisten the rims of 6 glasses by making a crosswise slit in a wedge of lime and running it around the rims. Dip in shallow container of kosher salt.
Fill glasses with ice up to the rims. Fill with tequila mix and garnish with a wedge of lime. Serve.