it really all depends on the conditions and the time of year. in the early season i hunt hay fields; alfalfa, grass, barley. usually spread consists of 6-7 dozen decoys in family groups. in the early season so from now until it starts getting cold you want some space between your decoys. in the late season i hunt corn and stubble fields, also winter wheat is killer but hard to hide in. when the lessers and cacklers arrive i throw out 10-15 dozen decoys and use heavy calling. call til they fall. when the late birds get here (greeters) you still want bigger spreads but keep calling to a dull roar. windy days it is good to hunt up wind of their roost and close to it. hunting near a roost (big body of water) is usually always good unless your seeing them fly a good distance to feed. to sum it all up you cant go wrong with corn. Good luck
Waterfowl hunting isn't a hobby, its a way of life.