First, draw football shaped figures across the middle of your piece of paper. You can have the paper both the long way, and the tall way.
Next, on one of the football shapes, draw an arc connecting the two points of the football. This is the basic method of the optical illusion.
Repeat the step you just did, and draw the arc. You continue this process until....
You get this! Notice how the arcs are bigger in some places than others, I think that that gives it a neat effect. You can also turn the direction of the arc to make it seem like its twisting.
Now do the same thing you did to the last football shape, to all of the others. :)
Now, go back into that area between the tubes, and draw more arcs.
Tear off extra paper, or, if you want a bigger design, flip your paper and repeat the same process on the other side of the football. I decided to just stop with half off the design.
The finished product! :) you can also add a splash of color instead of just plain black and white.
Thanks for watching my guide! Feel free to comment! :)