Divide 10 mint leaves and 2 teaspoons sugar into each glass. Press 4 to 6 times with a muddler until the mint smells strong — do not grind the leaves into paste.
Pour 2 tablespoons fresh lime juice into each glass and stir for about 10 seconds until the sugar dissolves.
Fill each glass almost to the top with about 1 cup crushed ice, pressing it down lightly.
Slowly pour ¾ cup chilled club soda down the inside of each glass.
Slide a long spoon to the bottom and lift the lime-mint base upward once or twice — do not stir vigorously.
Clap a mint sprig between your palms to release its aroma, then garnish each glass with the sprig and a lime wheel. Serve immediately.
