Post-Finale Interview with Jonathan Nolan & Lisa Joy
There are a bunch of interesting tidbits in these videos! It also provides a pretty important clue about how to figure out who is a host and who isn't:
In the case of a host, the camera will be ahead of them so that it is facing the host and leading them. This shows that the hosts are on predetermined paths. For example, with Teddy and Dolores, the camera is usually ahead of them and looking back at them.