Garnish suggestion: wedges of grapefruit and slices of lime
Salting a glass rim: Pour a generous amount of coarse salt into a shallow plate larger than the rim of the glass to be salted. Cut a very shallow line in thin wedge of a lime (about 1/8 inch long). Place the cut on the lime wedge onto the rim of the glass and gently run it the entire perimeter of the glass rim. Turn glass over, place into salt, gently wiggle it back and forth and remove. This should have produced a perfectly lined rim of salt!
Add all ingredients to a cocktail shaker filled with crushed ice. Shake and pour into a stemmed glass with salted rim* over ice.
Alternative method for a larger batch: the original recipe suggests mixing all ingredients in an ice filled pitcher (I’d put the ice in after mixing) and pouring into glasses from the pitcher.