One of the outstanding characteristics that actresses Anne Hathaway, Julia Roberts and Cameron Diaz have in common is a big, movie star smile. A wide smile projects confidence, makes the person you're talking to feel important and welcome and can even put you in a better mood. Conversely, a narrow smile may make you appear insincere or unenthusiastic. Learning to work a bigger smile can be useful in social situations, at work and help you take better pictures.
Stand in front of a mirror in a well-lit room. Smile as wide as you can, showing only your top row teeth, by pulling both lips apart and up.
Make sure your middle six teeth on the top row, as well as your side teeth, are visible. Then smile even wider, even if it feels forced. Make sure not to expose your gum line, show your tongue or have your teeth clenched.
Look at your eyes in the mirror as you smile. Imagine they are the eyes of the person you are talking to. Direct eye contact when smiling conveys confidence and warmth.
Think of something that makes you truly happy or that you find genuinely amusing. Imagine a beloved person or pet, a special memory or an episode of your favorite sitcom and allow it to be the catalyst of your smile. A genuine smile also engages the outer muscles surrounding the eyes that make crow's-feet and usually only occurs when a smile is natural and unforced.