Center for Data Redundancy:
So you've gotten your stuff copied over, and you can rest easy knowing that, even in the event of a tornado taking your house away, your data's safe. (I might be exaggerating a little—unless you live out on the wide open prairie. Happens.) But while you're good now, you're not good forever.
You might be wondering about where and how to keep all your backup media, how often you'll need to refresh your backups with new media, and perhaps just how to not forget about updating them with new data. This is the final step in your backup strategy, remember—vigilance. Here's what I suggest.
(#) Storing your media
How you should store each format is entirely up to what it can withstand. In general, technology prefers cool (but not cold), dry places. Excess heat and direct light (especially sunlight) should always be avoided—you'll cook the data right off your CD-Rs like that, and the solder joints and delicate components inside an external hard drive don't do much better. You can find exact temperatures and relative humidities, but you're not going around room-to-room with a thermometer, so I'll skip them.
For storing optical media, I hear a lot of people say not to store them horizontally and to use individual plastic/jewel cases. For what it's worth, my pressed music CDs have been stored on racks horizontally for years without issue, and I have a CD wallet of PS1 games, all of which still read and play fine (except for the ones I've scuffed a bit, of course). I have another CD wallet with discs about as old, again, which still play fine.
If you're paranoid, keep them upright like you would store books or vinyl records and use separate cases for each one, but otherwise, heat, humidity, and pressure—keep them low and comfortable.
For hard drives, another thing to consider is the lubricant inside the drive that allows it to spin. Alongside storing it in a comfortable, consistently-temperate location, you should make sure the drive gets regular use (every few months is good, but at least once a year) so that oil doesn't dry out.
(#) Refreshing your backups
Of course, you don't just stop generating data the moment you back everything up. You'll need to maintain regular backups to make sure you don't lose anything. The question of how often depends on the type of data and how much of it you're willing to lose by not backing up frequently enough. It all depends, so here's how my backups work out:
Computer reminders are the best for keeping on top of your backups. I use Trello's repeating cards function for the somnolescent.net and Somnocraft backups. Every so often, these cards reappear on one of my to-do board's lists, which makes sure I have something nagging me to do it until I do. If you have some other way you remind yourself to get things done, go for it.
(#) Keeping vigilant
Remember—being lazy is the quickest, fastest way to lose things. Small little bits of neglect add up over time, so a few more reminders for keeping your stuff safe:
(#) In summation
At this point, it's all up to you to decide what's important, what to save, and how best to keep it safe. It's a scary concept, losing things, but it's easily preventable provided you're aware and take the necessary steps ahead of time not to lose anything. Once you're aware, you'll notice your mindset on how you keep stuff start to change. Always ask yourself if there's anything important on the computer or device you're using that isn't anywhere else, and make sure that it is.
If you think like that, you'll never lose a thing.