Bip39 Last Word Or for pretty significant safety, you can "roll your own personal" seed phrase with dice or perhaps a calculator as offline solutions. A single set of mnemonic can be used to make many addresses. This method of producing account was introduced in BIP32 & BIP39 long time https://apollobookmarks.com/story18549110/ton-wallet-seed-phrase-generator-the-smart-trick-of-bip39-phrase-that-nobody-is-discussing