Best solution is offline storage.
If your interested im selling a Mycelium entropy that has been designed for making safe paper wallets.
https://bitcointalksearch.org/topic/wts-mycelium-entropy-1086132
No offense to you or anyone else. But I suggest people not buying hardware wallet or devices to make hardware wallets second hand.
Chances are it's a little over protective, but it defeats the purpose of cold storage if someone before you had access to the device before you.
If anyone buying it was concerned about malware they could always check it personally at https://mycelium.com/assets/entropy/me.html
From the site regarding security:
If you do not trust your Mycelium Entropy device and believe it may be backdoored, then this feature, sometimes also referred to as Diceware, is for you. It lets you add your own entropy (salt) to the mix so that:
• even though the salt is entered on your computer into settings.txt in a generally insecure way, its leakage does not compromise your key;
• if the device’s RNG is rigged in an undetectable way, your key is still secure because of the salt;
• the algorithm’s implementation is easily verified.
The current implementation is fairly simple and is called Type-1 salt. A more advanced algorithm has been proposed but has not been implemented yet.
• Salt is a string of up to 32 bytes, which is entered in hexadecimal after the salt1 keyword in settings.txt. It must contain a whole number of bytes, that is, an even number of hexadecimal digits, up to 64.
• Entropy is a 32-byte random number generated by Mycelium Entropy.
• Key = SHA-256 ( Salt || Entropy ), where || denotes concatenation.
o In the HD case, the first 128 bits of Key are used to construct the BIP-39 mnemonic.
• Entropy is printed alongside the private/public key pair for your verification.
Just speaking from cold storage it really does cause possible issues getting second hand. This is why hardware wallets such as Trezor have stickers showing if it was even opened.
And I'm not saying your a bad guy. Just in general people should stay far away from secondhand hardware wallets or devices used to create them. Its just good general security.
The entropy device i purchased did have a tamper proof sticker on it when i got it but that has obvioulsy been removed by myself.
I would not expect anyone just to take my word that it has not been tampered with, you do give good advise