Take some blueberries (let’s say a half handful) and put them in your cocktail shaker with sugar.
Muddle them together.
Congrats, you’ve just made blueberry syrup!
Add rum, lemon juice and blueberry liqueur to your blueberry syrup.
Add some ice.
Finish your shaking.
Nod in approval.
Fill your old-fashioned glass with ice.
Pour your now perfectly shaken cocktail into your glass.
Top with club soda.
That makes the fizz.
Garnish with blueberries.
That makes the sexy.