Essential oils for healthy hair need base oils such as sweet almond, apricot kernel, avocado, jojoba, evening primrose or sunflower. For one scalp treatment choose up to three essential oils and use five drops of each for two tablespoons of base oil. For very long hair you will probably need more oil. Warm the blended oils by placing the container in a bowl of boiling water, and then massage into the scalp. Wrap with a hot towel, leave for at least 15 minutes and then shampoo.