Add sugar cube (or simple syrup) to bottom of rocks glass.
Add Angostura bitters and optional orange bitters.
If using sugar cube, muddle until mostly dissolved.
Pour in bourbon or rye.
Add large ice cube or fill with ice cubes.
Stir for 10–20 seconds to chill and mix.
Peel orange strip, twist over drink to release oils, and drop in glass.
Garnish with cocktail cherry or orange slice if desired.
Notes
Bourbon provides a sweeter profile, while rye adds spice. Use a large ice cube to slow dilution. Avoid too much pith in the orange peel to prevent bitterness. Optional cherry or extra syrup can increase sweetness.