Place 8 basil leaves in your cocktail shaker & muddle them.
Add the fresh lemon juice.
Add the tequila.
Add 3 dashes bitters.
Add at least 5 ice cubes to the cocktail shaker and shake it well.
Place the desired amount of ice cubes into your serving glasses and pour out the mixture into your glasses.
Top each glass with 4 more bitters shakes each.