About 20 years ago, when we first started getting a flock of resident Canadas in my area, I made a dozen decoys out of old tires. I used them 2 seasons and killed a bunch of geese over them. From a distance they look surprisingly realistick. I can' t take credit for thinking of the idea - I have a book someplace with instructions.

Cut a tire in thirds to make three bodies. Then, cut head and neck silhouettes out of plywood and paint black with white cheek patches. You can either make the head/neck so the bottom end of them acts as a stake to stick in the ground, or cut them off at ground level and attach a piece of #9 wire for a stake. I think the wire works better. To use them, just put the tire sections on the ground tread side up, and stick a head/neck in the ground at one end.