Cut the bubble wrap to the size of the window pane with scissors.
Spray a film of water on the window using a spray bottle.
Apply the bubble wrap while the window is still wet and press it into place.
The bubble side goes toward the glass.
To remove the bubble wrap, just pull it off starting from a corner. You can save it and use it for several years. It does not leave a mess or stains on the window glass.
If you have trouble with the bubble wrap separating from the window when the film dries, you can try adding a little Glycerin to the water, but this probably won't be necessary.
A few small pieces of double back tape can be helpful on really stubborn windows.
The bubblewrap can be installed in the fall, and removed in the spring.
When you take the bubble wrap down, put a small number in on the upper right corner of each piece of bubble wrap, and write down which window that number goes with on a piece of paper. Save the paper for the installation next fall. This tells you instantly where each sheet goes, and which way its oriented.
Courtesy of www.builditsolar.com