well i am far from being an "expert" turkey hunter but i have picked up on many things over the years.

1. don't over call. alo of guys call almost non-stop when they hear a tom gobblein. that almost never works.
2. CAMMO!!! the most important aspect of turkey hunting. camoflaugeing yourself good enough is the key to bagging that big tom.
3. use an assortment of calls. ive noticed that you might be calling a tom in on your box call when at 100 yds he holds up. and no matter how hard you try he just wont come in. thats where multipul calls comes in handy. switching over from a box to a slate or mouth call might be all it takes to lure in the wary longbeard.