Smile, going back to a moment when you felt truly happy and content. Bring that feeling up into your whole body and then use this same smile to smile at yourself. You can choose an area that is giving you trouble: is it your digestion, your back or your shoulder? It could be used step by step for your entire body from your fingers to your toes, or directed to a specific problem area. Every time your shoulders feel tight, smile at them. Try to smile all day and see how you feel. You can give this smile to others and you will be surprised at how this simple meditation changes your mind and that of those around you.
As often as you can, try to turn artificial lights off. When the sun goes down, put away your phone, turn off your computer, turn off your lights, and sit quietly.