The Old-fashioned is another cocktail that is very simple, a great way to experience different whiskies, and essential to completing a cocktail repertoire. It will also introduce you to the bartending technique of muddling because this cocktail is more about the process than the ingredients. You begin by muddling sugar, bitters, and a slice of orange, then add ice and bourbon and stirring the mix. Some people prefer finishing it with club soda while traditionalists skip that touch.