Counting Vultures on Migration - Protocols, Methods, etc.

Migrating Turkey Vulture...or is it?

It's really exciting that fall migration is underway. As I'm sure most will agree, spending time at count sites is one of the great joys of the birding year. I'm helping count this year at a site that is new for me, Mohonk Preserve, in upstate New York. We won't see big numbers, but it's hawk watching. On most days, we have vultures in the sky. As most hawk watchers can attest, counting vultures can be a frustrating endeavor. This has been an issue for years and years. I haven't heard much discussion about it recently, so I'm curious how different sites handle counting these birds.  I know it is somewhat site-dependent, but might be productive to get some discussion going on this topic if there is enough of a discrepancy between sites in methodology.
What sort of vulture protocol do you have in place to ensure some consistency in data collection?