The essence of various techniques is to focus attention on a limited sphere or field.The sphere can be chosen according to suitability of individual.
1.Any object or sound outside the body of the meditator.
An object can be a flame of candle flower,a dot on the wall and rising or setting sun etc.This method is called tratak.Tratak means to gaze a particular object till eyedrop come out of eye without blinking eyes.
2.The body or it's parts
Attention on the body is called Deh Dharana or one can focus attention on any part of body e.g.heart,forehead.The attention can be movement of body. I.e.dancing and singing movements. Sound from the body.i g.Mantra Jap or recitation of Om.
3.The Breath- watching the movement of breath is called prana Dharana in yoga.
4.The mind- Observation of thoughts.This is called Chitta Dharana.
Meditation transforms mind from state of restlessness,confusion and dishormony to a state of tranquility,clarity and hormony which give s us a sense of total well being.