Rhombus Project Wiki
How to choose a good password
Creating strong passwords/passphrases that are hard to break might not be as easy as you think (if they should last few years to come)
Trezor wrote a very detailed and in-depth article about choosing strong passphrases for protecting recovery seeds. You can obviously follow this guide to password/passphrase-protect any kind of valuable information (like your Rhombus recovery seed).