How to make the perfect old fashioned: 

Find your best fancy tumbler. Or a mug.
Add ice
A large glug of bourbon. Stronger bourbon (45-50%) is better.
A splosh of your sugar syrup. Don't have any? Super easy recipe here
A couple of splashes of bitters (cherry is my favorite, peychauds or bitter union works well)
Garnish with a curl of orange peel or a morello cherry

The proportions of this cocktail are essential, otherwise you will render it almost undrinkable. If you don't get it spot on, don't worry, soldier on through, get it down and try again.

Remember practice makes perfect