I'm not a backup specialist, but do run my own backup infrastructure, so a few starting points. Not saying they will work in all environments, or even any scale environment though.

1. Figure out what's valuable and what needs backed up. Some will say "back up everything", but then you don't know what you need to restore and how to restore it! You need to know what's valuable. Is that source code? A complex application environment? Files in S3 storage? User generated files stored locally on a server? Data in a database?

2. Figure out where it's stored. Not always straightforward, but again necessary. Otherwise you won't know how to back it up, or recover it. Remember the cloud isn't a backup - when someone steals your production S3 keys, absent some careful configuration, they can dump and delete all your bucket contents...

Understand what you need to backup and how you'll recover it. If you are dealing with Windows based environments, consider the practicalities of getting these up again - windows isn't as nice as Linux (which can boot on any hardware within reason, modulo some bootloader settings in a few complex configurations)

3. Figure out how you're going to protect the data you back up. Now you've identified the crown jewels, don't just store them in plaintext and unencrypted on your laptop (!) If you're going to use encrypted backups, understand where the keys are stored and how they're used. More importantly, understand how you'll have the keys to decrypt the backups after a disaster.

4. Figure out how you'll stop a someone who gets in from deleting or accessing your backups. Assume they'll be attacked. Understand what the backup solutions offer in terms of security. Can you use asymmetric crypto so only public keys get stored on your servers? Can you use protection on an s3 storage bucket to prevent deletion, even with the access key? Etc.

5. Test doing backups. Then practice restoring to a non production environment to see what you missed. Document it all!

6. Set up monitoring so you know when something goes wrong with your backups. Gather and expose enough information to yourself that you know what's going on! This could be as simple as an automated email to yourself every morning, telling you the duration of the backup job, and the amount of data written, and amount changed since last time. But you need to monitor this. Don't just go for a failure alarm (have one of those, and make it fail-safe so it alerts if the backup didn't succeed, even if the backup script didn't run at all!) - also notify yourself on success so you are aware of the backups and what goes on.

7. Ensure you have enough copies. 1 isn't enough - what if the payment card on your storage account expires, or you get locked out? Or the company goes under? People normally say 3 backups in 2 locations, at least 1 off-premises.

8. Return to 1, because by now something has changed and you need to add more new things to the backup system.

There's all sorts of other things to consider like data consistency and whether operations on your systems are atomic (what happens if the backup snapshot is taken mid-operation in your app?) that you'll want to think about too.