Begin with a dead pan face with soft facial muscles and no expression (you can even start with a frown if that is where you find yourself). Either way you will end up smiling.
Do this as you read it, it will take 30 to 60 seconds.
1. Very very slowly begin to smile. So slowly that if someone were watching you it would be difficult for them to see any movement of your lips as you begin to smile. The smile should take between 30 and 60 seconds.
2. Feel the slight movement of the corners of your lips as they start to twitch and pull to the side.
3. Notice the sensation of a slight turn upward at the corners of the lips.
4. Notice the pull along the upper lip as the corners start to slowly move.
5. Feel the lower lip start to firm up.
6. Continue with the slow turn of the corners upward and notice the change of sensation between the upper lip and the nose.
7. Feel your cheeks becoming involved and the sensation at the cheek bones.
8. Do your lips start to part in the center or at the sides?
9. As your teeth become exposed what are you feeling?
10. As your smile continues notice your mood and allow it to shift along with the sensations you are feeling.
11. Let the smile continue to include your eyes and feel them open as the muscles around the eyes relax.
12. Feel the full smile with lips parted, cheeks flush and sides of the eyes engaged.
13. Note your thought, mood and feelings right now.
If you physically smile the neurochemistry associated with smiling is triggered. Therefore, there is a physical reason to feel happier just from moving your face into a smiling position.
might see it when you’re playing with your, golden retriever sending a tennis ball out into the pond a couple of hundred times a night. You may see it when you are doing the same thing with your Irish Terrier in the living room after work. Or your border collie may flash you a huge smile with his pearly whites when you get home from work and take her to the park to play. 
Living A Happier Life: Ideas, Inspiration & Practices 