Sakura Pigma Micron pen and DR PH Martin Radiant Concentrated Watercolors. One side was painted, then embellished with ink, scanned into Photoshop, copied, flipped and pasted to make the two sides. (Fairly large image, so I included a couple of details.) Silly but fun to do. A little "acid" and a few hours of gazing is all you need for a profound experience. Ask me how I know.
I modified the challenge a wee bit. I didn't use the same paper for the various drawings since I was using (top row, left to right) hard graphite pencils (3H to HB), watercolor pencils, (bottom row, left to right) brush pens and ballpoint pen. These media work best on very different paper textures and moisture absorbing qualities. The second picture shows the object of my study --- and the apparatus I use to hold botanical subjects. "Third hand" tools are very useful and cheap. This one was under $10 and serves my purposes well. Just FYI. (Each drawing/painting was scanned and composited in Photoshop.)
I think the best time of the weekend is driving home from work on Friday evening and thinking of all the potential of the weekend. Time to draw, paint, hang with family and friends and thank God for blessings.