I have a two DIY ring-flashes. My first one was made out of illustration board, and the second one was made of out of a bucket of fried chicken from our local restaurant. Here is my step by step tutorial on how to make your own DIY ring flash using the leftovers of a KFC dinner. (of course you can but a DIY ring flash kit or a totally pro solution as well, but then the KFC leftovers will be thrown away rather than recycled).
It takes about two hours to make one.