Measure the bourbon and bitters into a cocktail glass of choice. Traditionally old fashioned are made with one sugar cube, but I find them difficult to dissolve in the bourbon, so instead I opt for superfine sugar or simple syrup. I tend to like my old fashioned on the less sweet side of things so I add 1/2 a teaspoon of the sugar, but if you like a sweeter more traditional old fashion add up to 1 1/2 teaspoons of the sugar.
Stir until sugar is dissolved. Fill glass with a big handful of ice. Top with two maraschino cherries. Use a pairing knife to carefully cut a long thin strip of zest from the orange, twist it by wrapping it around your finger, then pop into the drink. Enjoy!