To create an offline Bitcoin wallet, use Electrum Bitcoin wallet software and follow these steps: -Open Electrum, click File -> New/Restore and create a name for the wallet. -Select any type of wallet except for "Watch Bitcoin addresses". -Select "Create a new seed" and click "Next". -You'll be given a mnemonic code with 12 words on it. It should be noted on paper and kept in a secure location. -Retype the mnemonic words one more time to finish. Your wallet will then be constructed and prepared for usage.