My daughter and her friend created their own tie dye t-shirts.
First, soak your t-shirt in a bowl with a 1/2 cup vinegar and enough water water to cover for 30 minutes.
Remove the t-shirt and wring all of the vinegar-water out.
Now, scrunch up and twist together sections of the t-shirt, holding them secure with rubber bands.
When done, drop on the food coloring, letting it bleed through the fabric.
Put your t-shirt in a bowl and set it out in the warm sunshine for a few hours and, when it feels nice and warm, rinse it in water until the water runs clear.
Then, hang it up on a hanger outside until dry.
It was messy but fun and the results were pretty good.