If you really want something easy, just use two potholders and sew them together. Sew a flap to one of the potholders and put a piece of velcro on the other potholder.
When I was desperate to have a small iron holder, I used my large potholder, the kind that has the thumb in it and it fit my iron perfectly. It wasn't the prettiest and I still haven't put a fastener on it, but it works and I am too lazy to do anything about it, as long as it still works. So far, no one has mention how lazy I am.