On the outside of our building we have a drop box located next to the main door that accesses the shop. In the box rests Ziploc bags, pencils, and pre-printed forms to use to identify your keys. Fill out the form, place it and the keys in a Ziploc bag and drop the keys through the hole that leads to a security box where we retrieve them in the morning.
The logic behind the Ziploc is that is what size fits in the hole! We also want to stress that house keys and lanyards be removed!