Keep your cryptocurrency keys securely!
Don't forget to make backup of your keys even if you use hardware wallet.
Hardware wallets use flash memory (like SSD disks, USB flash drives) and this type of memory is prone to failure, especially when it's not powered for weeks or more.
Hardware wallets are great for making secure transactions, however it's irresponsible to keep your private keys only on them (without backup).
I have a habit to write multiple copies of my important files when I use floppy disks, USB flash drives and optical disks (CD, DVD).
I not only use multiple mediums, but also write the file several times on every medium.
DVDs are more reliable than CDs, I prefer DVD+R (instead of DVD-R).
Here is my short guide: Archiving private keys - TLDR version