First you must charge the gemstone or Shiva lingam with positive energy, this is easily done simply by focusing on the task you want to do such as balancing and healing the aura or chakras together with an affirmation something like; may this crystal balance and heal my aura or the the aura of 'name'.

The gemstone or Shiva lingam will absorb energy and negativity from people which has to be discharged and cleansed, this is done by either mentally commanding the negativity to go and shaking it out, my preferred method is to put in in a jug and run it under a fast tap creating lots of bubbles in the water which releases negativity.

Keep the gemstone or Shiva lingam clean using your favourite polish, you can leave it near you when you are not using it but if you put it away then obviously wrap in tissue to avoid damage. Do not let other people use your gemstones as they will pick up their energy and it may take some time before it tunes back into your vibrations.