A solutions architect at a company is reviewing the costs of a multi-application environment spread across multiple Availability Zones within a single AWS Region. Following a recent acquisition, the company now manages two organizations within AWS Organizations. The company has established several service provider applications as AWS PrivateLink-powered VPC endpoint services in one organization and multiple service consumer applications in the other organization. The solutions architect has noticed that data transfer charges are significantly higher than anticipated and needs to reduce these costs. To achieve this, the solutions architect must provide guidelines for developers to follow when deploying services, with the aim of minimizing data transfer charges across the entire environment. Which two guidelines should the solutions architect recommend?