You might already be familiar with the Faketoshi story where a person claiming to be Satoshi Nakamoto said he was unable to prove his identity as he had lost his private keys after a hard drive failure. You should protect yourself from such events by making sure that you have adequate and secure backups in place.
1. Encrypt your wallet
Make sure that your wallet file is encrypted and password protected. Most wallet software will give you the option to password protect. Make sure you use it so that even if a hacker gets hold of your wallet file, they will be unable to access it immediately.
2. Keep an encrypted copy of your wallet file or private keys in external storage
To do this, you will first need a software that is able to encrypt files. If you do not have specialised software for this, you can actually use a zip program to create a password protected zip file to serve this purpose. 7zip does quite a good job as the native .7z file format will even hide the file names within the zip file!
Once you have the encrypted file, store it in external storage like a thumb drive or hard drive and keep it in a safe place.
3. Keep a paper wallet in a secure location
I am actually not in favour of paper wallets because it is just as safe as writing down your passwords on pieces of paper. If someone else gets a hold of it, they will be able to read it for themselves. One way you can possibly protect yourself is to come up with a "language" or writing scheme that only you will understand.
4. Keep an encrypted copy of your wallet file or private keys in another location
Let's say you have diligently followed the steps above and kept the external storage and paper wallets within a locked drawer in your home. Well, what happens if there is a fire and your entire home is burned down?
Which comes to the point that you actually need to store your files and keys in a secure secondary location, be it a trusted family member or friend, or even the cloud. Just make sure that the files are secured with a strong password in case anyone tries to snoop around. Paper wallets will be a bit harder to secure though.
