@simrin-- The way I do it is I throw my head down and massage the oil into my scalp in circular motions. Keeping the head down while doing this sends blood to the head and improves circulation.
Massaging the scalp with the oil on the tips of the fingers allows better absorption. I usually massage my scalp this way for fifteen minutes. Finally, I apply the oil the ends of my hair, let it sit for at least half an hour and then shower. Generally, the longer you keep the oil on your scalp, the more effective it will be.