You can use imagery in the following ways to reduce stress:
One common use of imagery in relaxation is to imagine a scene, place or event that you remember as peaceful, restful, beautiful and happy. You can bring all your senses into the image, with sounds of running water and birds, the smell of cut grass, the taste of cool white wine, the warmth of sun, etc. Use the imagined place as a retreat from stress and pressure.
Scenes can involve complex images such as lying on a beach in a deserted cove. You may 'see' cliffs, sea and sand around you, 'hear' the waves crashing against rocks, 'smell' the salt in the air, and feeling the warmth of the sun and a gently breeze on your body. Other images might include looking at a mountain view, swimming in a tropical pool, or whatever - you will be able to come up with the most effective images for yourself.
Other uses of imagery in relaxation involve mental pictures of stress flowing out of the body; or of stress, distractions and everyday concerns being folded away and locked into a padlocked chest.