I like to use the large 8 cup jars for this since I can store it and it lasts for about a week or so, but it doesn't usually last that long. The ratio is use is 1 cup of coarsely ground coffee per 4 cups of cold water. In this case I did 2 cups of coffee and 8 cups of water to fill my jar.
Once you pour the water into the grounds, make sure to stir or cover and tilt the jar back and forth to ensure all the grounds are soaked so they don't just stay at the top. This also assures you're getting the flavor of all the coffee that was added.
After 24 hours the coffee is ready to filter. I use my jarring funnel along with an old coffee machine filter. This does a good enough job but many people use a paper filter to assure the smoothest coffee possible. This is something i will try next, I did notice some tiny coffee particles though it was not bothersome. The resulting brew is a bit strong but suits my taste served over a fair amount of ice though water can be added to dilute it a bit. I would say this is most similar to having espresso that you would pour over ice, dilute with water or cream, or simply just have a smaller shot or two in a glass.
Here it is, a tasty smooth and refreshing glass of iced coffee. It is really so good and much better than other iced coffee I've had in the past. This is definitely going to be a part of my morning routine this summer. Give it a try and let me know what you think!