I got my foil a bit tighter than you have on yours. I got some heavy duty foil, it seemed to be easier to shape. I re-did both of mine a couple of times before I was happy with it. Not sure how to describe but I kind of laid mine there circling it around. It did take two pieces, kind of like yours is now. I took my time and shaped it in there. I let it hang out over the sides and bolted the lens back on so that it would hold the foil in place. Then came back and trimmed off what was hanging out.
I rode down a really dark back country road the other week just to try mine out and I was very happy with the results. I would say that I now probably have about 5 times the light output that I had before. I do need to adjust mine a little better but I am very happy with mine. And, you can not tell from looking at the bike that there is tin foil in the head lights.