Find somewhere nice and quiet where you will not be disturbed. Sit or lay down in a position that you feel comfortable in. Close your eyes and take in 3 deep breaths slowly. Put on some soothing music and light a candle or two if you feel it helps to relax you.
Once you are completely relaxed try to go back to one of your favourite memories. Re-live that memory. Try to remember how you felt and re-live those feelings. Re-discover that special time in your life. How did you feel? What was the memory about? Who shared this memory with you. Go back in time and re-live that happy memory. Take as long as you like on this exercise.