so watch the movies.........but u normally would use locator calls AFTER the morning .... turkeys will usually gobble on the roost before the sun comes up...get out there early and you can hear them gobble....to scout i never call to a bird..i will use locators if i have to but after a while they will get locator shy...so i just try to listed to where they gobble and try to watch what they do from a distance so as not to spook them.....when you are ready to hunt u can call lightly while they are on the roost or wait until they fly down (this is when scouting pays off if you know the birds usual route...they will not always do the same thing so keep that in mind too) then call to them some and see if you cannot get a bird your way...if a bird answers, via a gobble, to your call don't change..see what happends...if he doesn't answer that doesn't mean he doesn't like it...so wait a bit and try to call again...if still nothing..try and change it won't hurt anything........but again..watch some videos...honestly that is all i have ever done and it really pays off, IMO