Ensure each VPC that you have enabled has Flow Logs enabled and are being delivered
Ensure that your VPCs have flow logs enabled in order to understand traffic patterns and trouble shoot issues. Flow logs can also give you valuable data in case of a security breach to understand how lateral movement may have occurred. It is important to ensure that these logs are working as expected. This is considered a security best practice and should always be done. Ensuring this is enabled will help with NIST and PCI-DSS compliance.