Adhering to Azure Virtual Machine best practices is essential for achieving optimal performance, security, and cost-efficiency in the cloud. Fundamentally, this involves right-sizing VM instances by selecting the appropriate series and size from the Azure Compute Gallery to match workload requirements, while leveraging Azure Spot VMs for interruptible, fault-tolerant workloads to realize significant cost savings. For high availability, VMs should be deployed across Availability Zones or within an Availability Set to protect against datacenter-level failures. Security must be proactively managed by enforcing disk encryption with Azure Disk Encryption, configuring network security groups (NSGs) and Azure Firewall to enforce the principle of least privilege, and consistently applying system updates through Azure Update Manager. Furthermore, operational excellence is achieved by implementing Azure Backup for automated, geographically redundant recovery points, using Azure Monitor for performance tracking and alerting, and adopting an infrastructure-as-code approach with Azure Resource Manager (ARM) templates or Terraform for consistent, repeatable deployments. Collectively, these practices ensure a resilient, secure, and cost-managed VM environment.