Doing a basement reno and haven't sealed up all the walls yet. I have lots of spare hard disks. Gonna label a few drives, one primary and one emergency. They will be in anti-static bags, then silica gel and a ziploc bag. the note will say something like bitcoin cold storage november 2015. The discs will be blank but I will use a hex editor to leave a fun prank sentence or two on the boot sectors.