The reality is that almost every computer user will experience data loss at some point. It’s tempting to think that the solid state drives which come in most Macs these days are more reliable than spinning hard drives, but the truth is that they are not immune to failure, either. Device failure coupled with the risks posed by theft or natural disaster means that the odds are stacked against the average computer user.
External hard drives are practically getting cheaper by the minute; off-site backup services are affordable and extremely easy to set up; and OS X itself comes with excellent, built-in backup software.
In short, the greatest hurdle to overcome in terms of backing up your computer’s data is learning how to set things up. We’re here to get you past this hurdle.
There are 3 sections: local, cloud, and clone. These are the methods I follow and if you follow this advice, you'll always be in good shape when disaster strikes. This should be your go to link if you ever get asked how to properly backup your Mac.