From Pathfinder:
The most terrific fabric for
costumes is dads cast-off T-Shirts. Those promotional ones,
solid bright colors, just the right stretch, and being cotton they
are so breathable.
You use the fabric inside out thus eliminating the decal ad. You can even use scrap fabric for the inside of the costume ,no one ever sees it.
My other favorite stuff, is sheet foam, whatever shape you need , you cut it out and and use it as a template for your fabric, sew up a pocket and shove the foam in. It always looks so professional.
I've done bird wings and tail, headbands with ears, mini-mouse foam covered shoes. Ninja turtle shells, lady bug shell,and butterfly wings Even Thomas the Tank engine. I never spent more that $5. Usually on felt for trimmings.
From JANICER1:
I remember as a child my parents making a
Halloween costume by going to the thrift shops and just buying
clothes or as like being a princess just getting a dress from
there and making a wand with a star and then with aluminum
foil on it.
From Shannon:
I heard of
someone going as a bunch of grapes, and all you need is a
green t-shirt or whatever color you choose and lots of green or
purple balloons blown up and attached.