I shot my first one last weekend. Was in a popup, about 20-25 yds from the feeder, 2 Avian X Decoys (Tom/Hen). I used a box call, did some calling, mostly just purring I guess you'd call it, small drags on the call. I even "oinked" by mouth one time and got 'em to gobble. I take it to be just like duck hunting, more calling does not equal good calling. Less is often times better.
I've heard not to setup by the roost... go where the traffic is, if that's by your feeder, go there.
Good luck, have fun!