So let's test those new Old-Fashioned glasses, and what better way to do it than by making the drink that it got its name from - the Old-Fashioned.
As the name implies, this cocktail goes way back, to at least the 19th century. In fact, one of the first mentions of the word "cocktail" dates back to 1806, when it was defined as "a stimulating liquor, composed of spirits of any kind, sugar, water, and bitters". By the mid 1800's, many cocktails went on to become a little more complex, eventually leading some people to ask bartenders for one of those "old-fashioned" drinks instead. It is believed that this cocktail got its official name some time in the 1880's, but clearly it has been around long before that in some form.
And while this drink may have been considered "old-fashioned" by the 1880's already, it still hasn't lost one bit of its charm. We are going to make it today, and just like in the original definition of a cocktail, we won't need anything but sugar, water, bitters and some bourbon whiskey as our spirit of choice. Some people prefer rye, but I wanted to move one step closer to using up my bottle of bourbon.
While it's possible to use some simple syrup, we're going for good old sugar cubes instead. I even happen to have some poker themed ones:

Now as a Badugi player, I'm tempted to use all four of them, but we only need to put a single one into our glass. I chose the clubs this time.

Next, we'll need a few dashes of Angostura bitters.
How much is a dash anyway? Well, I looked it up, and while there is some debate about it, it would be about 1ml, or 1/8th of a teaspoon, or 15-20 drops. A pipette is not usually among a bartender's tools, and it's not like a few drops more would ruin the drink. Much like with a "pinch" in baking or cooking, it's probably best to just eyeball it and in this case give your opened bottle of Angostura bitters a good shake above the glass. What comes out should be about a dash.
The recipes even calls for "a few dashes"... can you get any more vague? I shook it twice, and the glass looked like in the picture below. The goal is to have just enough to saturate the sugar cube, maybe a few drops more.

The most common recipes only call for those dashes of Angostura bitters, but I've been informed that a few additional dashes of orange bitters can really improve this drink. Well, I just happen to have a bottle of orange bitters at home so I added an extra dash of it too.

Next, we would add "a few dashes" of water. How do we do that? I just filled a teaspoon with water and gently tapped it to add some bits to the glass until I felt that everything was well saturated. You may not notice much of a difference in the photo, but it looked like this:

Now we need to muddle all of this. As I described in my Caipirinha instructions, just gently press the muddle (or whatever tool your using) down and twist it around a bit.

Feel free to move that muddler around the glass. In the end, the mixture should look a little like this:

That was the complicated part. All we need to do now is to fill the glass with ice cubes and add 45ml of whiskey.

Now give it a stir and the Old-Fashioned is ready.

And that was my "test drive" for those new Old-Fashioned glasses. Pretty good stuff.