If i can't be out there before daylight and locate them by listening for gobbling on the roost, then I change to a "run and gun" style of hunting like hunting elk during the rut. I locate call, walk several hundred yards and locate call again. I keep doing this until I hear a tom answer, and then move as close to him as I safely can and then hunt him. I do more subtle hen calling, scratching leaves, etc. A tom with hens can be tough to call in, but sometimes you can get the hens stirred up and pull them in and the tom will follow. DO NOT overcall...just let them know there's a hen close by. They'll come if they're interested. Be patient, many times they'll hardly respond, but suddenly an hour later they'll show up. Also be aware of natural obstacles that may hang them up. If this happens, try to walk out around them and set up from a different direction. I've gotten several toms early in the morning fresh off the roost, but I've also probably gotten just as many between 8am to 3pm.