Visualizing calmness is highly effective in reducing stress. Imagine that you are in a hot shower and a wave of relaxation is washing your stress down the drain. Close your eyes, take three long, deep breaths, and spend few seconds picturing a relaxing scene, such as walking in a meadow, kneeling by a brook, or lying on the beach. Focus on the details of everything, the sights, the sounds, the smells. It will relax your mind instantly and this relaxation percolates to your body too.