This is a very important question which is not discussed often, well everyone doesn't have a safe. Although if you hold a huge amount it could be wise to get one.
I believe everyone has secure spots where they keep valuable possessions and documents, this could be a good place to keep your cold wallet, they should be well out of anyones reach and only accessible to you.

You can make multiple backups, although not too much so as not to lose count, two seems like a safe number. One can be kept with you in a different location but well within reach in case you need to import your keys quickly; the other should be stored in a different safe location such as a bank.