By memorizing it as a passphrase, or writing it down, or printing it as a QR code, or saving it to a flash drive, or (best) saving it in the tamper-resistant me

By memorizing it as a passphrase, or writing it down, or printing it as a QR code, or saving it to a flash drive, or (best) saving it in the tamper-resistant memory of a security token protected by a PIN or biometric? Unprompted, I don't believe many people asked for the most practical way to securely store 192 bits would answer "the orientations of twenty-five cubical dice in a plastic box".