I also use the galvanized.. is it galvanized? Yes it does look very different than how it used to look. shiny and bright now instead of the mottled grey..
I snip the corner and fold the edges over. I trim the corners of the folded over piece so I am not catching/cutting myself on them.. On the top piece fold over I use a 3/4 inch roofing/shingle nail in each corner, then use heavy 1/2 inch staples the rest of the way around.
btw.. I use the metal bending tool Perry showed in one of his posts, AND, I only put metal on the hives that I sell. My painted tele covers last to within a season of when the covers with metal on them last. Replacing them at less than three dollars each without the metal top is too easy to struggle with the metal for my own hives.
I use the cheapest paint I can get that still covers well. The fence and barn paint at $12.00 a gallon is not worth buying unless you want to put four to five coats of paint on.. Two to three coats of a better paint at 20 dollars a gallon is actually saving you money. No metal to buy either, so the cost of the paint becomes worthwhile. You dont typically PRY on your tele covers, so the only scratches and dings are from when you take them off, and flip them over onto the hard ground or rocks to set the boxes on as you inspect.