Here's an easy shamrock Hawaiian quilt block St. Patrick's Day card (easy if you have a cutting machine). Requires patience to hand cut.
I started with the letter "c" from the dingbat font Hawaiian Quilt2 and modified it with shamrock and heart shapes.
Hand cutting template PDF.
To hand cut, follow these instructions from tongs-paper-cutting to fold your paper and use the template.
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.