Place your rocks glass in the freezer for 2 to 3 minutes while you gather the rest of your ingredients. A cold glass keeps the drink cold longer and prevents the ice from melting too quickly once you pour everything in.

Remove the glass from the freezer and place the sugar cube at the bottom. Pour 2 to 3 dashes of Angostura bitters directly onto the sugar cube so it starts to dissolve and absorb the bitters.

Pour about 1/4 ounce of water (roughly one small splash) into the glass. This helps dissolve the sugar cube completely and creates the base liquid for your drink.

Using a muddler or the back of a spoon, gently press and twist the sugar cube until it breaks down and mixes with the bitters and water into a thick paste. Don't crush too hard or you'll create unwanted fine particles; aim for a dissolved, syrupy consistency.

Fill the glass with 2 to 4 large ice cubes, or break up smaller cubes if that's what you have. Large ice melts slower and keeps your drink cold without turning it into flavored water by the third sip.

Pour 1 to 2 ounces of sparkling water or club soda into the glass over the ice. This adds the volume and slight fizz that replaces the whiskey in a traditional old fashioned, while the carbonation also lightens the drink.

Using a bar spoon or regular spoon, stir the drink gently for about 10 to 15 seconds. This ensures the bitters, sugar, and sparkling water blend together smoothly and chill the entire drink evenly.

Cut a wide strip of orange peel using a vegetable peeler or citrus peeler. Hold it over the drink with the skin side facing down, then twist it sharply so the oils spray over the surface of the drink, then drop the peel into the glass as a garnish. Add a cherry on top if you like extra sweetness and that classic old fashioned look.