Wear a dark sweat suit with either a hooded sweatshirt or a brown knit hat.
Glue or tape leaves onto the hood/hat.
Cut the bottom out of a brown paper
yard waste bag. Cut a circle of cardboard with a hole in the middle that is
large enough to fit around your waist, and that will also fit inside the
bag.
Place the cardboard ring around your waist and put the bag on so it is
like a tube around your body. Cut arm holes in the appropriate places, or
just use clip-on suspenders to hold the bag up. Crumple newspapers and
stuff into the bag up to chest-level.
Fill the rest of the bag with leaves.
Thanks to Sue for this great idea!