I expose 4 sheets of 4x5 film in my camera with a stepped exposure sequence across each one done by pushing in the darkslide a little bit between clicks. I go from two stops under to two stops over in five steps. Because my darkroom is closeby I immediately develop all four sheets at different developing times. Within an hour I know the correct exposure for the scene. All I have to do is set a number on my light meter so that my usual metering strategy delivers the exposure reading I already know is correct. That's my film EI. And this test procedure also gives me the right development time either directly or by interpolation.
Certainly this is not a laboratory standard test but it is quick and the directness of it inspires confidence.