Explore the details of it. After a short time, you will feel tranquil and can introduce a positive affirmation. Repeat the phrase slowly, outloud and let the words sink in. Do this once a day and you will see a difference. It does take practice, so don't give up if it doesn't come easily at first.
Few things do.
There have been many studies done about visualization and meditation. It has helped people cure physical and mental conditions. The mind is very powerful and can change the condition of the body. A good book on the subject is Creative Visualization by Shakti Gawain. She has also written The Path of Transformation, Living in the Light and Creating True Prosperity, among other books, and has taught workshops around the year for more than twenty years.