Bip39 Mnemonic. Entropy values have to be sourced from a robust source of randomness. What this means is flipping a good coin, rolling a fair dice, noise measurements and so on. Don't use phrases from books, lyrics from songs, your birthday or steet address, keyboard mashing, or anything at all https://gen-directory.com/listings13033281/bip39-passphrase-generator-https-linktr-ee-bip39-bip39-words-an-overview