I ended up watercoloring some leaf backgrounds and using the leaf stamps on some and drawing in some leaves on some. Here are two of my tries.
These aren't cards yet, but they will be, since I like how they turned out. This one uses Navy Mid-tone ink from Hero Arts as the first layer...then I added the Unicorn ink in Blue. The greens are Tombow Markers in olive and dark green and I stamped the leaves in black.
For this one, I used the Blue Unicorn Ink for the first layer and then Distress Ink in Broken China. The light ink kind of muted the Broken China, but I liked the effect. I used the Hero Arts Neon Chartreuse to Blue for the leaves.
My goofy daughter (who's 21) came in after I'd stamped these and said, "What kind of stamping voodoo is this?" Apparently she's not seen the layered stamping yet, but it made an impression :) and she liked the look of it. Me too! Do you use layered stamps? I've found these flowers to be pretty easy to use.