I can't show the card I made this week as I made it for someone and haven't sent it yet. Instead, I've found some photos of cards I made last year when I was playing with corner dies.
Although a lot of corner dies cut a right-angled shape for you to add as a layer, there are one or two which are more like corner punches - they cut the edge of the corner, but leave it attached to the paper. A-ha, I thought, I can turn this inside-out. So I pencilled in a diagonal cross on the paper, fitted the die to each angle in turn and curled the paper outwards.
Quite effective, if I say so myself.