An image that is often given to help us develop the right understanding of practice is that of a vast empty room with an open window, through which a shaft of light is passing. In the shaft of light we can see specks of dust which, although floating everywhere in the empty space, are highlighted in the light. The shaft of light is the light of attention. The vast empty space is the mind. The specks of dust are the experiences of sights, sounds, smells, tastes, touches and mental impressions. The dust floats through empty space and if there’s right awareness, right mindfulness, we see it in perspective.
Ajahn Mumindo, Unexpected Freedom
In mindfulness meditation, we work to create the conditions favorable to the arising of mindfulness, relaxing the body and the mind, focusing the attention carefully but gently on a particular aspect of experience, while producing sufficient energy to remain alert without losing a sense of ease and tranquility. Under such conditions, properly sustained, mindfulness will emerge as if by some grace of the natural world, as if it were a gift of clarity from our deepest psyche to the turbid shallows of our mind. When it does, we gradually learn how to hold ourselves so that it lingers, to relocate or re-enact it when it fades, and to consistently water its roots and weed its soil so that it can blossom into a lovely and sustainable habit of heart and mind.
The purpose of meditation is to develop a sane relationship to experience. The struggles we have in life – shutting down, pushing away, feeling overwhelmed, and all the neurotic attachment — arise from the confusion we harbor about how to relate to the rich energy of the mind. When eating, we ingest, process, and eliminate food. But how do we digest our experience? It’s not so clear…The practice methods […] are designed to bring us into a sane relationship with our experience. As the great Tibetan Buddhist master Tilopa said to his disciple Naropa, “Son, it is not experiences themselves that bind you, but the way you cling to or reject them“
A good part of our automatic thinking is negative. Discontent comes naturally to us. Kids are discontented with their parents, parents are discontented with their teenagers, we are all discontented with our weight, and the prevalence of aesthetic surgery points to our discontent with the way we look. It is as if the brain is wired for discontent. With mindfulness we can become aware of this tendency. I remember distinctly the first time I became aware of the habit of negative thinking. I was at a staff meeting in work. All of a sudden, I noticed that I had a negative mental comment about everyone who spoke. Either he was incompetent, or he kept saying the same useless things, or he did not really understand the problem…Then a light bulb went on: Maybe the problems were in my mind rather than out there. Maybe I had a problem accepting things as they are, and people as they are. 
Mindfulbalance 