This is a wonderfully simple Tibetan Tantric meditation, which transmutes negativity at every level. The love energy of the heart is what 
does the transmuting. It is a very ancient meditation and for many sages it is regarded as the only meditation necessary.
Sit comfortably with your spine straight. Become aware of your body, how you are feeling physically, becoming aware of any aches, tensions or discomforts. Now become aware of how you are feeling emotionally, acknowledging any frustrations, anger, worries etc.
Now breathe into the discomforts/ fears and worries, bringing them up to the heart. Then breathe out love and compassion through the heart. Keep repeating this cycle for at least 10 minutes.
You will feel your pain, worries and fears melt away as they are transmuted by the love energy in your heart centre. You may experience aches in the heart as the heart opens more and more to love and compassion.