Leverage Azure Policies to flag issues for review with the audit status, and then leverage PowerShell scripts to identify and manage unattached disks in Azure Storage.
Identify and Manage Unattached Disks in Azure Storage
Azure Automation Comparing Runbooks and Functions
The recent annoucment that Azure Functions now has preview support for PowerShell was big news for me, and should be for a lot of others looking to automate standard azure deployment and operational tasks.