Just finished up this years scarecrow, so I thought I'd give you a look. Glued up and formed a styrofoam head, sized to fit the hat, and draped/formed damp burlap over it. After it dried I gave it a good coat of spar varnish which hardened it up. Sticks to fill out the body and a trenchcoat to finish. Not sure how it will hold up as I've never tried it before. Very quick to make. I will add some cornstalks, but haven't picked them up yet. Not great pics, the lighting
Lifesize Body Forms Its fairly cheap, less than $20 for a sturdy, water resistant and reusable form. Outside friendly. Just add your favorite costume! Use PVC frames and simply add empty 2 liter bottles for leg filler. Incidentally, the necks of the bottles fit 1/2" PVC pipe perfectly. Just use a 7/8" bit to drill a hole in the bottom of the bottle.