I personally like to get tight to the roost and call soft. I like to be as close as I can, but that takes a lot of stealthy tip-toeing in the dark. If I can get within 100yds, awesome. If not, then that is ok, but I want to be close enough where I can see them fly down. I don't call until that bird hits the ground, no matter how bad I want too. As soon as he hits the ground, I am the first "hen" to call and it's game on. I call soft and see how he responds (usually they come running). Then I read the bird, sometime the louder the better, even if they are up close.
My suggestion is if you haven't already, get yourself a glass-slate call and learn to get really good on it. You can get down right seductive with it. learn to do a real quiet "purrrrr-cluck." Kills em! Also learn to piss off hens. Like any women, they hate when they get cut-off or talked over. You get my drift...? If you got a henned-up bird as soon as hen starts yapping, cut her off and do it aggressively. Stop, and wait for her to start again, then cut her off again. If you can get her to come looking for a fight, you have that tom on a string.