Henna comes in powder form and must be mixed with liquid (boiled water or boiled tea) before you can apply it to your hair. Mix 50 g (1/2 cup) of henna with 60 ml (1/4 cup) of warm liquid and stir the solution to combine. Then, add more liquid little by little by spoonfuls (15 ml) as needed until the paste reaches a puree consistency. After mixing, cover with plastic wrap and let it sit for about 12 hours. Once you're ready to apply the dye, mix in a little more liquid until it's spreadable. Before applying henna, your hair needs to be clean. Use shampoo, but DO NOT condition your hair, as the oils in the conditioner can prevent the henna from penetrating the roots properly. Rinse the shampoo out thoroughly and dry your hair with a towel, a hairdryer, or air dry. Apply a little coconut oil, body lotion, or petroleum jelly to your hairline, including your forehead, neck, and ears, to prevent staining. Wear gloves; henna tends to spread, so it's a good idea to also use old clothes and a towel. Apply the henna. Do this in small sections until you've covered your entire head. Leave the henna on long enough to set. It usually takes between two and four hours. The longer you leave it on, the deeper and shinier the color will be. You can leave it on for up to six hours. Go to the shower, put your gloves back on, and rinse well, rubbing the conditioner into your hair to help the paste come out more easily. Continue applying conditioner and rinsing until the water runs clear and no trace of the paste remains in your hair.