I echo what Daver and Tombuck say about patience and staying with it. Mid to late morning can be very productive, especially if you've got some idea of where the birds go to feed/dust and can set up to intercept them.
Along the funnel lines, look for "holes" in fence lines. Many times a bird will hang up on the other side of a fence but if you can set up near an opening - natural or manmade - they'll usually take the path of least resistance.
If you hunt with a buddy, switch off calling ... if he's using a diaphragm, then you use a slate, or box. When you get a response, stick with the call that got him going. The guy closest should call at first but then switch to the other one so the bird might think his gal is moving on and he'd better get there quick.
When you set up, make sure you're shifted far enough to the right to cover a wide area (if you're right handed). I've had birds come in too far to my right and I'd have to been a contortionist to have gotten a shot off. Now I'll sit down first at what seems comfortable, then shift another 1/8-1/4 turn around the tree.
Man, 4th season seems a long way off ... I'm ready to go right now!!!
Good luck to all,
Threebeards