I do the same as you. I will scout early and try to shock gobble at first light - I try to make them gobble and when I do - I move quickly to cover as much ground as I can until fly down. Then I back up and try to see each bird that I found gobbling by glassing.
Then I will walk looking for the most amount of sign I can in an area. And I do this over and over and over and over and soon I have developed a pattern of knowing where to be and when to do it. Lots of tedious work - but in the end I bag my tom or toms.
Now I will shock gobble but once on the ground its crow calls or a duck call or a police whistle or a coyote howl ~ BUT I NEVER hen call.
JW