I felt intimidated too till a member of our ASG neighborhood group got us together at my house to try it. We started out at full strength with liquid and 1/2 yard of fabric in a gallon plastic ziplock plastic bag. We started with basic colors and each time we removed fabric from the bag, we added another cup of water so we got graduated shades of the same colors. They were beautiful.
The fabric had a marble effect and no two were alike. We used a bleached, high quality muslin. My fabric was a success but my porch floor will never be the same.