I figured out, right away, when I first started drawing Zentangles that I would need a method for keeping track of how to draw specific tangles. After a bit of experimentation, I settled on testing the pattern in a small sketch book. I could draw it once or several times, just to see if I could do it, and if I would like working with a particular design. Then, I created “step-out” cards which illustrated each step in the process. I didn‘t think a lot about the size, just that they had to be around the same size as a playing card. I had a box that I though would hold them all, and I created an alphabetical index for it.
I needed a way to both practice and to have some kind of encyclopedia of the tangles that I use. So now, I use these tangle trading cards. I‘m not sure exactly where this design came from, but I‘m sure if you look on the internet you can find something that will work for you. These are set up on an 8-1/2″ by 11″ format, 9 cards to the page, in a .pdf file on my computer so I can print them out on inexpensive card stock whenever I need more.