Bip39 Utils Or for pretty large security, you could "roll your own private" seed phrase with dice or possibly a calculator as offline approaches. One list of mnemonic may be used to produce several addresses. This process of creating account was introduced in BIP32 & BIP39 while in the past. https://doctorbookmark.com/story18676702/gen-seed-the-best-side-of-seed-phrase-generator