This is a simple pose that is great to relax the mind and improve digestion. It is believed that a good digestive system is the key to a healthy body. Therefore this asana is ideal to improve hair growth. Vajrasana also massages the kanda spot about 12 inches above the anus that is the point of convergence for over 72,000 nerves.
Steps to do this pose: All you need to do is place a yoga mat on the floor. Kneel on the mat, and let the top surface of your feet touch the mat such that your heels are pointing upwards. Now gently place your buttocks on your heels. It is important to note that your heels are on either side of your anus. Now place both your palms on your knees, facing downwards. Close your eye and breath in deeply at a steady rate.
Source: The health site