Combine the tequila, triple sec, simple syrup and lime juice in a large pitcher and chill if possible.
Pour salt into a shallow dish or small plate to a depth of about 1/4 inch. Moisten the rim of each glass with a wedge of lime, then invert the glass into the salt and twirl around until evenly coated. Add several ice cubes to each glass.
To serve, fill a cocktail shaker 2/3 full with ice. Pour one serving of margarita into the shaker and shake vigorously for 15 seconds. Strain into a prepared glass and garnish with a lime wheel. Repeat for additional servings, replacing the ice in the shaker as needed.