Unlimited Lock Cylinder Shims
Buy new stuff and get free lock shims!
Almost everything purchased from a physical store these days has a magnetic anti theft device attached, or more often recently, inside the packaging where it is harder to remove while in-store! Regardless of type, color, or placement, there is always at least one thin metal strip free floating inside each.
Recovering the shims
Tilt the security device on it's end, then tap it on the table a few times to shake any free floating bits to the bottom of the container. They are rarely clear on the back but it made for nice pictures!
I use scissors to cut open the container, but try to get as close to the top as possible; static can prevent the strips from moving even when shaken.