There is this hair oil that they sell in the supermarkets which works wonders. Its castor oil (zayt kharwaa). Other oils that are just as good are called Vatika and Amla. Apply the oil to the hair emphasising on the roots by massaging it in. Leave in and wrap hair in a towel for at least 2 hours then wash hair as normal.

You can also use this oil on eyebrows if you find that they are thinning. On eyebrows, leave oil on overnight and wash off in the morning.