I took a class with Jill Cardinal at Oregon Art Supply in Eugene. We had a great deal of fun, painting our own tape and stamping with hand made stamps.
Hand made stamps are my favorite. I quickly carved this eye stamp in class. The feather stamps, I made previously.
I am always on the look out for good abstract design stamps and tend to over-think it. Jill and I were playing with "random designs" and she showed me her best trick. In her box of carving material scraps, there are many discarded designs and broken, or cut-off pieces. They make GREAT random stamps! Cut off a few edges and try lining them up in various ways to make repeating patterns. Many of my "fancy" washi tape designs were made with these so called scraps.
We played a game: on person cuts lines into a stamp section and hands it to the next person, who cuts out a piece that looks fun to stamp with. We tried lining up the prints every which way. See more examples on the bottom photo.