- always write down your wallet seeds (+passphrase) on a piece of paper and keep it somewhere safe. Also, it's not a good idea to rely on your memory to store your passphrase (passwords, etc..)
If anyone want to follow this particular advice, make sure to write the passphrase on a separate paper on a separate storage.
It's not a good idea to keep them together where a thief can easily get both data together.
Otherwise, it'll defeat the purpose of the BIP39 Passphrase.