Bip39. Entropy values needs to be sourced from a strong source of randomness. This suggests flipping a fair coin, rolling a good dice, sound measurements and many others. Usually do not use phrases from publications, lyrics from tracks, your birthday or steet deal with, keyboard mashing, or something you're thinking https://directoryorg.com/listings13102737/bip39-seed-phrase-https-linktr-ee-bip39-a-simple-key-for-bip39-github-unveiled