I've often heard--and I'm sure you have also--that when you're getting your picture taken, you should say, "Cheese!" It's supposed to give you the most relaxed smile. It's supposed to make it look like you're not posing. Here's another suggestion:
Live in the present moment.
When good things happen in your life, smile about it.
When you do things well, smile about it.
When you make someone feel good, smile about it.
When you complete something you're proud of, smile about it.
When you finish a job that you've worked hard on for months, smile about it.
In other words, celebrate your successes--and if you must say it, say, "Cheese!"
Just a little something to make you smile. Have a great week!
(Photo taken after a speaking engagement at the Sedona Rouge, Sedona, 2010, provided by Christine K. Bailey)