Which are some of the cost optimization opportunities with Amazon EBS volumes?

To help optimize costs, you should monitor your EBS volumes and remove any unused or unattached volumes that are no longer required. You should avoid over-provisioning performance settings for IOPS and for throughput. When possible, you should use gp3 volumes, not io2 volumes, for volumes requiring lower, less than 16.000 sustained IOPS. Newer volume types are typically less expensive and include more capabilities for the cost. You should provision only the smallest amount of capacity required, and use dynamic volumes to increase the volume size and provisioned performance over time.