Best practice to run Docker, according to Wiki, is to use a VM and not a LXC:
But I guess you meant best practice when using a LXC.
If you want to run application containers, for example, Docker images, it is recommended that you run them inside a Proxmox QEMU VM. This will give you all the advantages of application containerization, while also providing the benefits that VMs offer, such as strong isolation from the host and the ability to live-migrate, which otherwise isn’t possible with containers.
But I guess you meant best practice when using a LXC.