AWS Cloud Cost Optimization.

Optimizing costs in the AWS cloud requires a comprehensive approach that spans across various AWS services. Here are ten best practices:

1. Right-sizing Resources: Ensure you are using the right types and sizes for your cloud resources based on your workload requirements. AWS provides tools to monitor and assess your utilization, which can guide you in right-sizing your resources.
2. Auto Scaling: AWS Auto Scaling automatically adjusts your resource capacity to maintain steady, predictable performance at the lowest possible cost. By using this service, you can optimize costs and performance for multiple resources and services.
3. Use Reserved Instances or Savings Plans: Both Reserved Instances (RIs) and Savings Plans offer significant discounts compared to on-demand instance pricing. These are commitments to use a certain level of resources for a one to three year term.
4. Spot Instances: Spot Instances are available at up to a 90% discount compared to On-Demand prices. They are perfect for applications with flexible start and end times, applications that are only feasible at very low compute prices, or users with urgent computing needs for large amounts of additional capacity.
5. Delete or Stop Unused Instances: Any instances that are not in use should either be stopped or terminated. This also applies to other resources like unattached EBS volumes and aged snapshots.
6. Leverage CloudFront for Content Delivery: By using AWS CloudFront for content delivery, you can reduce the load on your instances, thus reducing costs.
7. Monitor and Track Service Usage: Use AWS Cost Explorer and AWS Budgets to monitor your costs and usage. Set custom cost and usage alerts so that you are aware when you're spending more than expected.
8. Optimize Data Storage: Regularly review your data storage needs and use lifecycle policies and different storage classes in S3, like S3 Standard-IA or S3 Glacier, for long-term, less frequently accessed, and archival data.
9. Use AWS Cost and Usage Report (CUR): This report provides the most comprehensive set of cost and usage data available. It helps you identify trends, pinpoint cost drivers, and detect anomalies.
10. Architect for Cost: Consider cost optimization when architecting solutions. Use AWS Well-Architected Framework to help you build secure, high-performing, resilient, and efficient infrastructure.

Remember that each use case is unique, and different strategies may apply depending on the specific needs of your applications or services. Continually monitoring, analyzing, and adjusting your resources can lead to significant cost savings.