Automatically Make Snapshots for EC2
by Max Rohde,
A quick Google search reveals that there are quite a few different approaches for automatically creating snapshots for EC2 images (such as here,聽here and here).
All of these are rather difficult to do.
Thankfully, after some more searching around I found a great way to schedule regular snapshots using AWS CloudWatch.
CloudWatch supports a built-in target for 'Create a snapshot of an EBS volume':
For details of how this can be set up, see the excellent step-by-step instructions on the CloudWatch Documentation.