Start by taking a cocktail shaker, and filling it around a quarter of the way with ice cubes – cracked ice can also be used, but this can water drinks down somewhat, and since the fun of the Suburban cocktail is its potency, you might want to stick to regular ice cubes.
Once the shaker is packed with the ice, add in the Angostura bitters, and follow this up with the port, rum and whiskey respectively.
Now that everything is in, screw on the lid of the cocktail shaker, making sure it is tight, and will not come off easily. Then, proceed to grasp the cocktail shaker firmly, and give it a couple of vigorous shakes (for around 15 seconds or so), in order to make sure all the ingredients are mixed together, and the drink is thoroughly well-blended.
After the drink has been blended to perfection, add 2-3 ice cubes to your old-fashioned bar glass (you can also use a rocks or bucket glass), and pour the drink out into this. Make sure you do not fill the glass all the way up – leave an inch or two of space at the top. Your Suburban cocktail is now ready – serve neat and chilled, without any frivolous garnishes.