First, visit your local thrift store and storm the old lady dresses.
Second: Find a Dress of a solid material that is the length you desire from the waist down.
Third: Buy the dress for SUPER CHEAP and take it home.
Forth: Cut the Skirt off of the dress from the waist down. Then using a seam ripper, take out the stitches in one of the side seams or back seam, which ever.
Fifth: Hem up the sides from the seams that you just ripped open.
Then fold down and sew the top so that you can run elastic through it .
Then cut a piece of elastic at about 10 inches or long enought to loosely fit around the youngsters neck.
Then, run the elastic through the top, as the tail end is just hidden tack it down with your sewing machine so that end doesn't pull through.
Then, (ya, then) you will finish fishing your elastic to the other side and as you do your neck will gather. When pulled through take the other end down.
Add Velcro for a closure. DO NOT USE A TIE, BUTTON or any other device that would prevent the cape from coming off if pulled. This will prevent strangulation.
Personalize and Add a mask and you're done.
One Old Lady Dress from a Thrift Store: $1.00
Mask: $ 1.00
The thrill of being 7 and a Super Hero