Anecdotal sources suggest that if you're hunting in fields, basic white garbage bags make excellent decoys. It can make up a believable illusion of geese gathered on the ground, and typically entice the geese to land so the hunter can bag his prize.
Many hunters use white trash bags to increase the number of decoys without a lot of additional cost. But it is labor intensive and you should always have to schedule in an extra couple of hours to haul in and set up and extra time allotted to pick up and haul out.
Whether you're a casual goose gunner or a die-hard veteran, there's a good chance you have experienced days afield that end in frustration. Check out some experts' tips for successful goose-hunting at Ducks.org.