Summarize this article:

Make an effort to smile at times when you usually don’t. For example, smile at the bus driver on your morning commute to school or work even if you’re tired. Smiles attract attention, but it's the right kind of attention and can help make the world a more positive place.  Smiling at work or during other professional occasions is not going to make you seem unprofessional. It can actually humanize you and make you appear more approachable so you can communicate with co-workers more effectively. A smile makes you seem "real." It may make you feel more vulnerable, but that means you’re opening yourself up to others, which provides the opportunity for more meaningful connections. Whether it's for a photo or to keep your mother happy when relatives you can't stand visit, smiling on demand can be difficult. That’s usually because you lack a genuine reason for smiling. In these situations, try to remember past reasons for smiling and focus on the techniques that you’ve practiced.  For a photo, smile a little harder than you think you should. That will ensure that your smile is as photogenic as possible. If you prefer to smile with your mouth closed, try placing your tongue on the roof of your mouth. That helps tighten the muscles in your face and neck for a more natural smile. To encourage yourself to smile, it helps to understand the benefits that a smile can bring to your day. You’ll smile more often if you know how it affects the way you feel and interact with others.  Smiling improves your appearance. A person who is smiling is usually thought of as more attractive than someone who is frowning, pouting, or sporting a blank expression. A smile can often say more than words can. If you've hurt someone, made a mistake, or are just in a bad mood, a smile can help others know that you’re apologetic and want to make amends. Smiling creates trust and rapport. It is a simple way to make other people feel more comfortable around you so it’s easier to form a bond and communicate. A smile can make you feel good. Even if you're feeling down, focus on happy thoughts and allow yourself to smile. It can release endorphins that help improve your mood.  Smiling can make other people feel good too. An open-mouthed smile is visible from fairly far away, so it can help put almost anyone whose path you cross at ease.

Summary:
Smile when you normally wouldn't. Expect smiling to be difficult in some situations. Enjoy the many benefits of a smile.