Mindfulness can be achieved through trained meditational practices derived from Buddhism. Mindfulness can be nurtured through the practice of sitting meditation. In learning mindfulness meditation you will focus attention on your breathing or a single thought, as wandering thoughts come up, you will work to re-focus on your breathing or single thought.
Typically beginners start with short periods of 10 minutes or so, as you practice regularly, it will become easier to keep your attention focused on breathing or a single thought. Eventually your awareness can extend beyond your breathe to your thoughts, feelings and actions.