You will need one 100% cotton shirt, Sharpies or Bic permanent markers, eye droppers and rubbing alcohol. It's easy-peasy. Lay the shirt flat, placing a piece of cardboard inside the shirt to prevent bleeding through. Make dots in a circle, pressing hard to have lots of ink on the fabric, then drop rubbing alcohol in the center, and watch the ink bleed. I threw them in a hot dryer to set the color. The kids all loved this project. And I am now working on a tote bag.
M was the most diligent, which probably comes from being the oldest. I think hers turned out the best, just don't tell the others!