Bip39. Entropy values should be sourced from a powerful source of randomness. This means flipping a good coin, rolling a good dice, noise measurements and so on. Don't use phrases from books, lyrics from music, your birthday or steet deal with, keyboard mashing, or something you think is random, since https://viewsdirectory.com/listings13080683/bip39-npm-https-linktr-ee-bip39-bip39-mnemonic-generator-fundamentals-explained