I'm always running short on ATC's (Artist Trading Cards) as I use them instead of business cards. I prefer to give a handmade one-of-a-kind piece of art. I've also been known to leave a few here and there, almost as RAZ (Random Acts of Zentangle) however I do include my name and blog address on the back. Sometimes I warm up or practice on an ATC. Here are a few I've done lately. For the continuous Maryhill, I just kept drawing string lines until I had lots of triangles and then filled in with Maryhill.
This panda is a stamped image from Onyx Xpression that was a scrap. Months ago I was making a card and it wasn't satisfactory, maybe the color wasn't right, maybe I wasn't happy with the amount of ink I put down...who knows, I can't even tell you what ink I used at the time. I cut it down to 2.5"x3.5", rounded the corners, and tried to figure what it needed. I ended up adding Keeko as an all over pattern (except over the pandas) and the effect is really nice. A little hard to see in a photograph tho.
I tried the same thing with this Quandary by adding the Keeko in stardust again. It has a nice subtle all over shimmer.
Here is a technique I've used before, cleaning my stencil onto ATC's. I used the color it left as my string and added Tipple and Yincut in Sakura metallic gellyrolls.
And again, this time Shattuck with Sakura moonlights.
This one just shows how forgiving Maryhill is. I really wasn't taking my time and my lines were quite shaky. Shading helps a lot! You'll also find Printemps and Diva Dance.