Add gin, triple sec, and fresh lemon juice to a cocktail shaker.
Fill the shaker with ice.
Shake vigorously for 10–12 seconds until well chilled.
Double-strain into a chilled cocktail glass.
Garnish with a lemon twist.
Harry MacElhone of Harry's New York Bar in Paris is widely credited with refining the modern White Lady recipe in the 1920s. For extra silkiness and a frothy texture, many bartenders add a half egg white - shake dry first before adding ice.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including White Lady.