Due to the pay-per-use model of cloud computing, there are many ways to optimize costs. Starting with the reduction in unused instances, you can decrease the cost of computing resources. Cloud providers like AWS offer the option of spot instances, reserved instances, and other such features that you can leverage to reduce the cost of computing resources.

Data transfers are also a significant contributor to cloud costs which you can reduce through CDN(Content Delivery Network). There are many cloud providers like AWS and Cloudflare that offer CDNs for minimizing data transfer costs. 

Another way to optimize cloud costs is by ensuring the removal of unwanted files. Cloud architects can configure the rule of data deletion or migration between different types of storage through programming. For example, you can store active data in Azure Blob storage while programing data with frequent access errors stored in Azure Cold Blob storage.

API calls are charged per object, and you can reduce the cost by using batch objects. It helps in decreasing the API access costs. Another optimization that you can induce is by enabling auto-scaling of resources. With auto-scaling, you can save money on slow periods or days when there is lower traffic on your cloud apps.