Now, here's the funny thing. I'm not crazy about flavored coffees when I'm drinking it hot. I don't even add sugar. Just a little milk, and that's enough. But iced coffee is different. I like added flavors, and a little sweetness is fine.
By the time I'm done adding things to my chilly coffee, I've got a frothy, happy, chilly coffee drink that's a lot more substantial than a cup of coffee, but not quite as rich as a milkshake. And a lot cheaper than the cold coffee drinks you can buy at coffee shops. Possibly better for you, depending on what you add to it.
To get that coffee-shop richness, you'll need to use something with a little more body than plain milk - half-and-half is one choice, but you could use nonfat non-dairy creamer. Soy milk, almond milk, ice cream, coconut milk, coconut cream, or rice milk would work.
For a thicker, slushie-like consistency, you need to start with cold coffee. So pour an extra cup and stash it in the refrigerator for later use. Another option it to freeze leftover coffee in an ice cube tray and use that instead of plain ice cubes.
Iced Coffee (with variations)
1 standard coffee cup strong brewed coffee cold
1/2 as much milk (or milk substitute) as you have coffee
1 tablespoon sugar (or to taste)
1 teaspoon vanilla extract
Optional flavorings* (to taste): almond or hazelnut extract, chocolate syrup, nutella, raspberry syrup, cinnamon, peppermint extract, butter pecan flavoring - or any coffee syrup flavor that you like.
To get the best texture, blend the ice cubes first, until you have small pieces. Add the coffee, milk, sugar, vanilla extract, and any optional flavors. Blend until smooth.
Serve. A dollop of whipped cream would be a nice garnish.
*For an after-dinner treat, coffee liqueur, amaretto, rum, hazelnut liqueur, or other liqueurs would make a nice addition.