Smile from your liver, from your heart, from your stomach. Smile from every cell in your body!
I have to say this meditation gets me giddy! Which, I believe, is what meditation is about; feeling that bliss, joy within.
And, again, you don't have to sit to do this meditation, you can do it anywhere. Take a moment out of your day to just smile from within. I bet it will also lead to a smile on the outside too!
PHOTO CREDIT: https://www.flickr.com/photos/mmoorr/