I think kellyquinn has a great idea on watching around the watering holes. They will almost always come into water when they can for a drink or what ever..
Where I hunt they become call shy before the season opens up on them for the most part. This is because there is a lot of unexperienced turkey hunters trying to test their calling out 2 weeks prior to opening day. I tend to try and get out past those areas if I can. But, when I can not I will find a location I know they have been going to and set up 100 to 150 yards back. I will look for an opening that they can strut in when trying to attract a hen. One of the things I look for in there is droppings whether from the tom or hens. Because we all know if hens are around the toms are not far away. For as far as them gobbling back that really never happened very much during the last 2 years. I hardly hear a gobble and then there is one right in front of me.. This way they tend to catch me by surprise. I also sometimes resort to just a hen decoy when setting up in these kinds of location as I just want the tom looking for a hen and not so much of a fight. I hope this helps.. Sometimes the clearing is just an old logging or skidder road if you have them there is all it takes.. The birds may still be wise but are less cautious in this type of surrounding..