Place the lime wedges and blueberries in the rocks glass.
Add the sugar on top of the fruit.
Use the muddler to press gently, releasing juice and oils without crushing seeds.
Fill the glass with ice cubes.
Pour the cachaça over the ice.
Stir with the bar spoon until the sugar dissolves and the drink is chilled.
Serve immediately without straining.
Notes
Use larger ice cubes to avoid dilution. Chill the glass before making the drink. Substitute white rum if cachaça is unavailable. Garnish with whole berries and a lime wedge for presentation.