Fill shaker with ice. Add whiskey, cranberry juice, simple syrup, and lemon juice.
Shake until well chilled.
Strain into a highball or Collins glass filled with fresh ice.
Top with club soda, sparkling water, or ginger ale. Stir gently.
Garnish with cranberries, rosemary, lime wedge, or mint leaves as desired.
Notes
Use ginger ale for a sweeter drink, or sparkling water to keep it light. Unsweetened cranberry juice is tart; adjust simple syrup as needed. Load up on ice to keep the fizz strong.