You can buy stickers that deteriorate if broken, like warranty void if removed. In fact some of the commercial options use this.
Check out the 10 second video for the Crypto Key Stack at the end of this page.
The home printable paper wallets also use stickers you can purchase.
That's good, unique tape is best, in case, they have the chase to come back after ordering it on Amazon.
Crypto key stack is actually where I got my idea from. I just thought buying 1$ steel plates was cheaper...and less suspicious if people are checking out my mail. Building a deck, eh? Writing your name on your tools, eh?
I think the more measures you take the better. Sadly, chances are if it gets compromised it is someone you know and trust.
When I worked in IT, often it would be relatives who were scammed into thinking they were helping along with the occasional bad apple.