For the third card, I tried using an oak leaf I found on my front deck that had turned a deep brownish red. It's very faint here because it was already dried out, but I liked it anyway. Since the leaf was oak, I mounted it over the acorn dsp.
This was a fun technique and very easy to do--thanks, Cyndy!
TIP: Fresh leaves that haven't fallen off the tree or bush work best. Look for leaves that have an interesting shape or distinct edges.