People have burned incense for cleansing purposes and ritual ceremonies for a long time.  In addition to incense, bark, resins, roots, leaves and flowers have been burned.  Fragrant smoke has always been a fascinating symbol of life, death and transcendence.  In China incense is burned to provide pleasant fragrances for rooms and clothing, to communicate with the gods and to drive out evil spirits.  Burning incense during I Ching readings is essential because it creates the right atmosphere in which to receive the divine wisdom or the pure breath of the gods.  In recent times, aromatherapy uses a variety of fragrances as a way to  touch the soul. Feng shui treatment burns incense to cleanse or remove negative energies from a room or home and has given the ritual of burning incense new meaning.  Daily incense burning is highly recommended in places where sha (negative) energies are particularly strong, as in sickrooms, waiting rooms, places used for meditation or therapy.  If you don't like the odor of charcoal, a wire grid suspended over a fire-proof vessel can be substituted.  A tea light can provide the necessary heat.  (You might want to try burning spices that have outlived their useful time as a way to enjoy some new fragrances.)  Times to burn incense include moving into a new home, after an illness or conflict, anytime, depending on individual preferences or as a regular ritual, daily as support during meditation or relaxation.  Affirmation to use while burning incense:  I am cleansing my space from everything that is out of balance and turning towards light.  I am letting go of the past and living peacefully, with joy.  I am relaxed, allowing life to flow through me with lightness.  Source: Feng Shi Symbols by Christine M. Bradler & Joachim Alfred P. Scheiner