I personally generated my private keys on a bootable usb stick with a fresh Linux Mint install on it, while my HDD’s and internet connection were decoupled. Copied it to three other USB sticks as well, that I spread over three different buildings where I trust they’ll be safe. Of course they are also password protected. The USB sticks will never be plugged into any system until I’m ready to immediately send them to MaidSafe’s burn address to exchange for actual SafeCoin.