Place the sugar cube (or sugar) in a mixing glass. Add 2-3 dashes of Angostura bitters to the glass.
Add a few drops of plain water to the glass and stir until the sugar dissolves. This helps mellow the drink and create a syrupy consistency.
Fill the mixing glass with ice, add the bourbon or whiskey, and stir until well-chilled.
Place a single, large ice cube into an Old Fashioned glass, and strain cocktail over the ice cube.
Garnish your old fashioned cocktails with a twist of orange or lemon peel. To do this, hold the peel over the glass, skin side facing the drink, and give it a good twist to release the citrus oils, then rub it around the rim of the glass before dropping it in.
Add a maraschino cherry for added color if desired.
Notes
Please see post for bourbon and whiskey suggestions, as well as variations and substitutions - it's a very long list!