I’ve been practicing with the local wildlife. Finally figured out how to implement “back button” focusing on the Sony A7III, which helps enormously with a telephoto. No more shifting focus to the wrong piece of grass.
The other big trick it to be non-threatening. I take a small chair and sit. The deer watch for a while and then go back to deer stuff (eating mostly).
The sony 600mm lens is pretty good as this detail shows.