Gather your supplies like small dishes of water, paper towels and rubber gloves. You will use the water and paper towels for cleaning the paint brushes and gloves to protect your hands from the dye.
Take a clean potato, drop one drop of dye directly on the potatoes and use a paint brush to spread it around. You can cover the entire potato with one color of dye or do multiple colors. Add more dye as you need, but one drop will go along ways.
Place the dyed potato on paper towels and let dry for 10 minutes. Then spray a light coating of hairspray on the potato to prevent the dye from rubbing off. Let dry for give minutes.