You can wrap the item in cloth to help prevent edges from poking holes in the plastic and/or aluminum layers, though this is not necessary.
For more protection, you can use more layers of plastic and foil. The foil is referred to as a conductive layer. The metal allows radiation to travel along its surface but not through it. [1] X Research source
A Faraday cage is designed to protect devices from an EMP (electromagnetic pulse) blast. This is a high intensity blast of radiation that comes from a weapon or a naturally powerful source (e. g. the sun). [2] X Research source You can also use a Faraday cage to block a cell phone or radio from getting reception, or prevent your expensive car from being stolen by protecting its (keyless entry) keyfob. In this case, you would need fewer layers since the radiation is much weaker than an EMP blast. Adding adhesives like glue between each layer will make your faraday cage more sturdy and permanent, but it will be harder to remove.
For added insulation, you can line the inside of the can with cardboard before the plastic layer goes in. You can add layers of foil and additional layers of plastic wrap inside to increase the effectiveness of the Faraday cage. More layers will make the cage more effective, even if the layers themselves are thin.
Once the devices are inside, you can attach the lid with adhesives or bolt it on for a more sturdy cage. It is also wise to tie the cage down to a beam or bolt it to the wall using a metal strap to make your cage a permanent fixture.
