This is a guide on how to encrypt and backup your private keys and passwords. Please remember that the files are only as safe and secure as your computer + your chosen password. The password generation is very useful to keep different and secure passwords for all the places you interact with. Encrypting your passwords and files is something you really ought to do.
There are great devices that can do this for you.
There are other options for this, some are cloud based that create an automatic backup of your file. I would not use that for your privatekeys, because that means you have to trust the third party as well.
Remember to use a secure password for your file!
In KeePassX, you can not only save your passwords, but you can generate new ones at a custom length. This is a great way to generate strong passwords to use on sites. So you only ever need to remember one password (to your encrypted file).
Backup your file! - You don't want to feel the regret of not doing it.
ALWAYS HIT SAVE - if you don't, your entry is not saved...
Your password and file is only as safe as your computer - Keep your computer clean and safe.
Most secure way is to only ever use a Computer without internet access - This means that you never expose the device you use KeePassX on towards the internet. This is how you should generate private keys as well!
If you look for a more convenient way to do this, buy a hardware wallet! - There are plenty of options out there for good hardware wallets.