In undertaking asanas it is desirable to have a teacher who can demonstrate the correct positions and correct any bad habits that develop in your performance of the asanas. It is useful at the beginning to take an introductory course or set of lessons in hatha yoga if it is available to you. These lessons will start you on the right path. Even if a qualified teacher is not available, a friend who has had a teacher can point out errors in your asanas which will help you.
 A note of caution, however. Teachers of hatha yoga who teach only hatha yoga often mistake the shadow for the substance. Although they may be able to point out correct postures and procedures, many of these teachers do not themselves comprehend the implications of the term yoga…
 Ram Dass “Remember: Be Here Now”