I think the trick is learning when to release the reins. When I do use them I try to release them as soon as I get the response I'm wanting and keep little to no tension on them. When I got Vida she had no "Whoa" and knew no voice commands. Although she has gotten pretty good with just voice, sometimes ya gotta tap the brakes
If we were just doing arena work, I don't think I would need reins/bit at all.