I used the same reflective foil that Flyguy mentioned in his original post. I found it at home depot.
I set it up so that the foil was about an inch above the bottom of the pot. Also in my case, the base of my pot is much larger than the stove top's heating element, so the foil didn't get burnt.
By the way, a few days later when I was at the home brew store, I saw the same reflective foil on sale at the store (for a higher price of course).