Mindfulness is a tenet adopted from Buddhism. It is used not just in that philosophical program but also in treatment of mental health problems such as anxiety and depression.
In terms of creativity, mindfulness is a good state of mind to engage in. Mindfulness is the belief that people should pay attention to the moment in order to prevent thoughts of the past and fears about the future from crowding in and inhibiting peace and orderly decision-making.
In a state of mindfulness, one can pay attention to one's thoughts seriously enough to capture creative ideas that arise. In the rush of daily routine or in the obsessiveness over past suffering and future pain, a creative thought can sometimes be washed out by the intense emotions of fear and sadness. So says Richard W. Sears in his book Mindfulness.
I would argue as well that creativity depends on being aware of the moment as a space of meaningful consciousness. To be creative, one must be able to put the present in the context of the past and the future. The reverse--making the past and the future more important than the present--is non-creative. One creates in the present, though not by ignoring the past and future, either. Instead, mindfulness argues that the present has meaning because of its different status from the past and the future. People who ignore the present are also denying the truth of the past and not preparing fully for the onset of the future. In the end, the present is where newness arises, and creativity is a manifestation of newness.