what guidelines must be followed?

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Guidelines for FCoE VLANs and Virtual Interfaces
Follow these guidelines when configuring FCoE VLANs and Virtual Fiber Channel (vFC) Interfaces:

** Each vFC interface must be bound to an FCoE-enabled Ethernet or EtherChannel interface or to the MAC address of a remotely connected adapter. FCoE is supported on 10-Gigabit Ethernet interfaces. The Ethernet or EtherChannel interface that you bind to the vFC interface must be configured as follows:
The Ethernet or EtherChannel interface must be a trunk port (use the switchport mode trunk command).
The FCoE VLAN that corresponds to a vFC’s VSAN must be in the allowed VLAN list.
You must not configure an FCoE VLAN as the native VLAN of the trunk port.

Note
The native VLAN is the default VLAN on a trunk. Any untagged frames transit the trunk as native VLAN traffic.

You should use an FCoE VLAN only for FCoE.
Do not use the default VLAN, VLAN1, as an FCoE VLAN.
You must configure the Ethernet interface as PortFast (use the spanning-tree port type edge trunk command).

Note
You are not required to configure trunking on the server interface even if the switch interface is configured with trunking enabled. All non-FCoE traffic from the server will be passed on the native VLAN.

The vFC interface can be bound to Ethernet port-channels with multiple member ports connected to FIP snooping bridges.
Each vFC interface is associated with only one VSAN.
You must map any VSAN with associated vFC interfaces to a dedicated FCOE-enabled VLAN.
FCoE is not supported on private VLANs.
If the converged access switches (in the same SAN fabric or in another) need to be connected to each other over Ethernet links for a LAN alternate path, then you must explicitly configure such links to exclude all FCoE VLANs from membership.
You must use separate FCoE VLANs for FCoE in SAN-A and SAN-B fabrics.
FCoE connectivity to pre-FIP CNAs over virtual port channels (vPCs) is not supported.