Every scenario is different. It's possible to do a lot of different ways. You can scout until you know their routes and set up along their daily travel route though some view that as bushwacking. You can bust a flock up and call them back in. You can kick them off the roost after fly up, before fly down, or if you run into them on the ground. The run and gun technique works well in the fall for me. I'll move along quietly and offer some calls out, either hard yelping, kee kees, cutting, or gobbler yelps or clucks to see if i can ellicit a response from any birds. If you do, you can then decide which tactic is best based on time of day, terrain, etc. Another way, and this is tough, is just sneaking within shooting distance. I know that sounds like a lot, but lately I've sharpened my woodsmanship skills pretty well to the point where I snuck to within about 20 yards of a group of hens last week, and then within about 30 yards a few days later on another group. It's just whatever works for the particular instance. Turkey hunting is a strange game, one I truly live for, but it's also a very frustrating one sometimes.
-Ron