Juice the citrus: Squeeze fresh blood orange juice and lemon juice. Fresh is key here — the color and flavor of fresh blood orange juice can't be replicated.
Combine ingredients: Add bourbon, blood orange juice, lemon juice, and simple syrup to a cocktail shaker.
Add ice and shake: Fill the shaker with ice and shake vigorously for 15-20 seconds until well-chilled and slightly frothy.
Strain: Strain into a rocks glass over a large ice cube or fresh ice.
Garnish: Add a blood orange slice or wheel to the rim. A brandied cherry adds a nice touch if you have them.
Serve immediately and enjoy that gorgeous color.