I took a disposable cup and placed it under the shirt and wrapped a rubber band around it. I also took some old cardboard and placed between the layers of the shirt.
Then, I grabbed my Sharpies and started making dots to form a circle. I drew six small dots like this:Then I took another colored Sharpie and drew six more dots in the spaces I had left of the circle. The various directions I read said to use an eye/medicine dropper to place approximately 15 drops of rubbing alcohol on the Sharpie. I did not have an eye/medicine dropper so I improvised with a drinking straw.