Bip39. Entropy values should be sourced from a strong source of randomness. This means flipping a fair coin, rolling a fair dice, noise measurements etc. Will not use phrases from textbooks, lyrics from tunes, your birthday or steet tackle, keyboard mashing, or just about anything you think that is random, https://directoryunit.com/listings13084924/bip39-vs-slip39-https-linktr-ee-bip39-bip39-word-list-no-further-a-mystery