I now take a ground blind to the field so I am not limited to hunting right up next to trees, corn or a fence line. This allows me to conceal myself and also allows me a good chance for those birds that approach me from the back. I like a blind that is 48 inches tall and maybe 10 fee long so I can wrap it 3/4 quarters around me.
As for calls I will use one to get birds to make a pass at my decoys but I really do not call that often.
Remember, movement is what scares birds the most so make sure you move slowly and try to avoid sudden jerky movements either while shooting or waiting for the birds to fly over.