It would be useful to know your workload or primary services used (EC2, CloudFront, RDS, S3...) in order to point to advice.

My top 3:

- Buy reserved EC2/RDS/Elasticache capacity - this can be done even with no upfront payment, but you save more with up-front payment. This will save you roughly 30-60%. - Use spot instances. - For S3, use Reduced Redundancy storage where appropriate.