This is what I do. I started with Bitcoin back in 2011 then added Namecoin and then Monero. I have not lost any crypto currency nor fiat for that matter to either computer hacks or "Goxed" exchanges (including Mt Gox itself). By the way I still keep my Mt Gox Yubikey on my keychain as a powerful reminder to not leave funds in an exchange longer than is strictly necessary for trading.
Here is what I do
1) Install GNU/Linux as the host. If one is using Windows XP or Windows 7 migrating to Ubuntu is way easier for non techs than migrating to Windows 8.x or Windows 10.
2) Do not enter any passwords or store unencrypted keys wallets etc on any computer where Microsoft Windows is the host (even in a GNU/Linux virtual machine) or on any virtual Microsoft Windows guest. This is critical. Windows malware is a very common cause for lost coins!
3) Run your own full node or nodes with an encrypted wallet.
4) Make multiple backups of the Keys files for Monero: wallet.bin.keys together with wallet.bin.address.txt as well as the Monero words. For Bitcoin (reference client) wallet.dat etc.
5) Get Encryption software either use the tools built into GNU/Linux or for the not so tech minded use Truecrypt. Yes this is still good and easy to use
https://www.grc.com/misc/truecrypt/truecrypt.htm6) Store these
encrypted backups in many different safe places one can think of using as many varied technologies and locations as one can think of. These can range from multiple computer hard drives, usb hard drives, optical media, floppy disks, online email accounts, online services, bank safety deposit boxes, with friends, relatives etc. The NSA shared folders in Windows 10, iCloud etc are perfectly fine for this, remember it was encrypted on GNU/Linux!
7) Regularly test these backups on a second node on a different computer to make sure everything works. Perform a dummy run on a simulated house burns down scenario, disaster etc. Can you get your coins after fleeing a disaster etc?
Use mobile wallets / online wallets for minimal daily spending amounts only say under 200 XMR equivalent at current exchange rates.
9) Consider Estate planing.
10) Be creative. A 5.25 in floppy disk in a bank safety deposit box can be very effective. If the safety deposit box is compromised, the obsolete technology will slow down an attacker long enough in order for the rightful owner to empty the wallet. On the other hand the executor of your estate has ample time to figure out how to read the floppy disk. This can work to store encryption passwords for example.