Definitely no set pattern to calling. I'll echo a hen though. They don't like that.

If I know where the birds are roosting and they are henned up I will start somewhere close to the roost say 100 yds or so and let them fly down, wait about 10 minutes after they have flown down and start with some soft yelps and purrs if the are not henned up I will do some soft tree yelps to try and get the bird to fly down in my direction but if you do this when they are henned up alot of times the hen will fly down the opposite direction and the toms will follow. If you start calling and the bird cuts you off with a gobble in the middle of your sequence stop calling because the bird is on his way to come find you. It is nice to hear that bird gobble but if you call him too much then he thinks your coming to him. some soft purrs when he gets 40 or 30 yards from you will usually drive em crazy. If you don`t know where the birds are in the morning try and locate with owl hoot right before daylight breaks on until first light and then crow call in the later part of the morning I usually don`t try and locate by yelping unless nothing else is working because sometimes they are right there and will be on top of ya before you get set up. If you get a bird that is hung up (won`t come in) start doing some aggressive cutting and cackles or maybe some fighting purrs to imitate hens fighting you could even try some aggressive yelps to sound like an old boss hen this works real well when they are henned up too. You can even start walking away from the bird while yelping then set down again after about 50 or so yards sometimes that will trigger the bird to think your leaving the area and he will come and try and stop ya. I know everybody is different in their tactics this is just some of the ways I have been successful in the past.

Is there one call out there that is better then the other? meaning either electronic or other?