Part of the answer depends on how you're fulfilling licenses: with FlexNet Operations, or by hand, or...? You could issue node-locked licenses, but that could be a hassle if you're creating them by hand.
Another option is to use "activatable" trusted storage licenses: you could provide the customer with a count of licenses, and their client machines would have to touch an internal server (at their site) once to detach a license, and then never have to contact the server again. The programming and reference guide for trusted storage-based licensing (ProgRef-TS.pdf) has more information about that option.
We create the licenses by hand, well, we use a utility. It only takes a few seconds to generate a license.
As a scenario, let's say the customer does not have any sort of networking capabilities. Let's say they don't even have networking cards installed on the machines. They could not even contact the activation server one time. They are also constantly changing and adding hardware.
It's difficult to say what's "best" at this level of detail; it depends on your relationship with the customer, your business processes, and all that. One option is to issue a single license file with a node-locked wildcard HOSTID identifier (in HOSTNAME or INTERNET, for example)...
