A few years ago, I made an iris-folded card as part of a craft class on a cruise ship. I was thinking about it recently, and decided to have another go. Finding a template online was really easy, I sized it to match an aperture card and picked out four matching papers.
It's best to use thin papers for this as the card gets quite bulky, I'd forgotten just how thick the pattern gets by the time you finish. This template has 32 pieces of paper in it. I enjoyed this for a change, and I'm happy with the results, but I don't think I'll be making very many similar cards (though I would like to try an oval some time).