Step 3: The Coil
What you are going to need for this is, a soup can, and, a coffee can or small metal garbage can. Emphasis on metal. You need something solid to wrap the copper around.
Since copper is a soft metal it is easy to work with and bend by hand. This is also one of its weakest points. When bending the tubing you have to be careful not to kink it. If you do, its almost impossible to get it back to the original shape by hand. I know. I tried.
You have to take the tubing and wrap it around the the soup can. To do this, you have to take one end of the tubing and roll it around the soup can. The easiest way I found to do this is to, leave the tubing in the box, press the tubing round the can with the palm of your hand, and rotate the can, firmly pressing the tubing against the can.
Once you get about 6 wraps, you'll have to push the can down so you can do more wraps. Once you have about 8-12 inches of wraps you can move on to the garbage can wraps. This is much easier than the soup can. Use the same technique as the can but this time you need to wrap in the opposite direction. This way you'll have both ends of the tubing end at the same place.
Why did I do it this way? Well, I wanted more surface to ice exposure. If you do it in one big coil, you are wasting a lot of ice surface in the middle.