Modifications to Chuck Gardner's design:

I use fun foam where one sheet is self adhesive. Stiffening material sandwiched between is not necessary and neater than stapling edges together.
I also used a round hole punch at the junctions of the sharp angle cuts to relieve a little of the stress on the corners and minimize tearing.
Durability isn't a major concern, considering the $2 investment.

I found that the self adhesive Velcro tabs wouldn't stick well to the foam sheets, so I glued them in place with a better adhesive. Staples would also work.

The flash can be turned any direction to compliment the position of the camera and subject, or a flash bracket is even better.