Scripts and third party tools can make managing dozens or hundreds of cloud accounts more manageable. Cost engineering and usage reporting tend to be the first tools to be implemented, but others quickly follow. A number of campuses have put together list of common tools here: https://docs.google.com/document/d/1dU4_LL3QMNNgmSd5yfwCji4Syk0v1W1wFPsvIxsg_sc/edit
Two prong attack:
Auto-tag resources
Send an email notification to account manage with total spend and resource usage
More information can be found here: https://cloudmaven.github.io/documentation/aws_cost_notification_system.html