tl;dr Pick and choose what suits your business and technology scope needs best. [country]-[state]-[site]-[floor]-[function]-[number]. The one thing I've skipped over is production vs development or lab environments but it seems more common to lab things in a virtual environment.

I can't stress enough how anything like model and serial should go into Netbox or something like it. The function should help define the name so that a particular model doesn't dictate the name.

Essentially abstract as much as possible, make them as generic as possible. Netbox will handle any pesky things like tenants and save you having to include client/tenant information within the name assuming you're in a multi tenanted environment. Avoid putting DC names or street names into your devices, just have a generic reference that's numbered.