I find I have to play with it every time, it’s usually trial and error.
I recommend getting a larger monitor too, I’ve been caught where it looks fine in the EX3’s display but back in editing not so much. I also notice that if LED lights are set closer to the brighter side of things the flicker tends to not be as noticeable. I’m not sure if you have to shoot electronics such as BlackBerry’s, computer screen or etc but same process there.
Usually I just pop the shutter into ECS mode and start rolling through the speeds until I find the minimum flicker.
Auto is okay, but it sometimes will stray on you. Example being I was shooting some b-roll near a window and panned slightly towards a desk – once I was near the desk you could see a slight flicker until the auto was able to compensate for the flicking of the Kino-Flos.