Make the espresso in an espresso machine, and pour it over the ice.
Top with cold water and stir to mix everything together.
Serve.
Notes
If you don’t have an espresso machine, you can make Instant Espresso with instant espresso granules.
A classic Iced Americano does not include milk - that's a latte. An Americano is just an espresso made with water.
Add cold water. The amount is up to you, but typically, it's about 6 to 12 ounces (or more if you prefer a milder taste). I mostly stick with the ice, but if I add water, it's about 3 to 4 ounces because I like a strong coffee. The amount of water you add will depend on how diluted you want your drink to be.
Espresso Strength: You can make it as strong as you want, but I suggest starting with 2 ounces of espresso per serving and then moving up if you want to.
A single shot of espresso is about 1 ounce (30 ml). A double shot (often referred to as a "doppio") is roughly 2 ounces (60 ml).