Women in western countries have been using this little trick since ages. As a final rinse for their hair, they add a little Apple cider vinegar to the water. (You can also use diluted distilled vinegar available at any local food store). This gives a great shine to the hair. This is especially recommended for all those living in areas with hard water. You can also make a vinegar and essential oil rinse and keep it handy for this purpose in the bath.