You are either on the X, or you are running traffic. The latter can be difficult and frustrating.
IMO, flags work better than calls. As said, calling a lot will make them ignore you. Go to the park and watch the geese when a new flock comes in. The group in the air is calling and the ones on the group only get vocal as they land to hold their ground.
Buy a blind and learn to camo it into the field. This is 10x more important than calling.
Rogers sporting goods, the 2.0 is pretty good at $170 and 2 on there for $100