Make homemade henna hair dye by combining 1/2 cup henna powder, 1/2 cup hot water, coffee or tea, 1 teaspoon lemon juice or apple cider vinegar, 1 tablespoon ground cinnamon, and 1 teaspoon fresh ginger. Also required are plastic gloves, a terrycloth towel or turban, a plastic shower cap, a zippered plastic bag, a wide elastic hairband, a non-metal spoon, a comb, brush and a timer.
Begin by washing your hair with clarifying shampoo. Place the henna in a large glass or non-reactive bowl. Heat the water, coffee or tea and add it to the henna, along with the remaining ingredients. Stir until the mixture is creamy and smooth, taking care not to leave any lumps. Add the mixture to the plastic bag and seal it. Cut a hole in the corner of the bag to allow a small amount of the mixture to pass through when squeezed. Put on plastic gloves and cover yourself and the work space with a towel. Apply the henna mixture, beginning at the roots, and work outward. Work quickly, and keep the hair moist. When all hair has been covered, put on the plastic shower cap.
Allow the henna to set for at least three hours. The longer it sets, the deeper the resulting color. Next, rinse your hair with warm water, combing out the paste, but do not wash it. Optionally, use a conditioner on the hair at this time. A hot oil treatment is also fine at this time, but do not shampoo or use other styling products for at least 48 hours.