you can do this using Electrum or using https://www.bitaddress.org/
- Download an open-source (Linux) system using the official URL.
- Download Electrum using the official URL & verify the signature.
- Boot your OS from an offline PC (It is better to remove internet Hardware parts) and install Electrum wallet (that contain the private key).
- Create a watch-only wallet.
- use online PC to access to that wallet (watch only).
- Create a new transaction ----> click Preview ----> check everything is correct ----> click save or generating a QR code.
- open your offline OS -----> open Electrum ----> Load Transaction or use a QR code ----> check it is correct -----> click Sign ----> enter your password.
- back to your online PC ---> Load Transaction ----> Broadcast it.
- Download an open-source (Linux) system using the official URL.
- Download Electrum using the official URL & verify the signature.
- Boot your OS from an offline PC (It is better to remove internet Hardware parts) and install Electrum wallet (that contain the private key).
- Create a watch-only wallet.
- use online PC to access to that wallet (watch only).
- Create a new transaction ----> click Preview ----> check everything is correct ----> click save or generating a QR code.
- open your offline OS -----> open Electrum ----> Load Transaction or use a QR code ----> check it is correct -----> click Sign ----> enter your password.
- back to your online PC ---> Load Transaction ----> Broadcast it.
For this you need to have 2 PCs and fiddle around with them, not practical at all if you need to use it, only for deep freeze usage, not even cold storage.
For the amount of money you can buy Trezor One or Ledger nano it's just isn't worth the fuss and you get the same thing, 2 points of security that mitigate attack if one point gets infected.