New Year's Suggestion: do a computer backup today, before the alcohol starts. Start a habit. With decent software, it's easy.
Seriously: with something like Time Machine, you just need to make sure the external drive is plugged in and turned on, it should happen automatically after that.
If you're cautious, part of your reason for taking backups is to protect against system corruption, so you won't leave the backup drive turned on, or perhaps even plugged in. Today, I spotted that Mrs Troll's main computer was last backed up on August 27th. Fixed that, by connecting the drive and turning it on. No further action needed, the backups are happening. It's that easy.
As a simple new year's resolution “Take a backup at least every month”. Set a date of “the last day of the month”, so that if you notice it's the first of the month and you haven't done a backup, you're already late, so you get to it quickly. Then use a calendar to schedule it. Perhaps Google Calendar. Recurring event, with an SMS reminder, “Do computer backups”.
If you want to add complexity, so you feel like you're doing something, you can either use backup software that's not so easy (but I suggest hunting around for something as easy as the Mac's Time Machine) or you can add a few routine tasks to the process.
I suggest: “Back up to local machine my data from the cloud, immediately before the system backup”.
If you use Google products, then see www.dataliberation.org for links to how to get your data out, and then go to www.google.com/takeout/ to get the small but often essential stuff. Including Contacts information. Then https://www.google.com/calendar/exporticalzip to get all your calendars as a zip file. To back up Gmail, it's more awkward if you're not strong on tech, but you're basically looking at enabling IMAP (temporarily if you normally have it off) and using a tool to sync the content to a local store. If you use a search engine and search for “backup Gmail” you'll get plenty of helpful guides.
If anyone has used good software for desktop systems and casual users to make it easy to one-click fetch (perhaps walking through any needed authentication) for all the cloud data sources someone has, pull to local disk, and then trigger a system backup, please leave a comment with details.
-The Grumpy Troll