Mindfulness is a very simple form of meditation that was little known in the West until recently. A typical meditation consists of focusing your full attention on your breath as it flows in and out of your body. Focusing on each breath in this way allows you to observe your thoughts as they arise in your mind and, little by little, to let go of struggling with them. You come to realise that thoughts come and go of their own accord; that you are not your thoughts. You can watch as they appear in your mind, seemingly from thin air, and watch again as they disappear, like a soap bubble bursting. You come to the profound understanding that thoughts and feelings (including negative ones) are transient. They come and they go, and ultimately, you have a choice about whether to act on them or not.I found it right here.
Mindfulness is about observation without criticism; being compassionate with yourself. When unhappiness or stress hover overhead, rather than taking it all personally, you learn to treat them as if they were black clouds in the sky, and to observe them with friendly curiosity as they drift past. In essence, mindfulness allows you to catch negative thought patterns before they tip you into a downward spiral. It begins the process of putting you back in control of your life.