Add the tequila, triple sec, lime juice and agave into a large pitcher or carafe and stir to combine.
Refrigerate the pitcher or carafe until ready to serve.
When ready to serve, prepare the glasses. Add kosher salt to a shallow bowl. Rub the edge of the cocktail glass with the lime wedge then dip the glass in the salt.
Give the margarita a quick stir. Fill the glasses with ice and pour the margaritas over the top.
Notes
Do not add ice to the pitcher. Chill the margarita mixture and add ice directly to glasses to prevent dilution.