Smile

Smiling is an indispensable element of nonverbal social interaction. So easy to perform, yet it doesn't come easy to a lot of people. Many shy people avoid very spontaneous expressions that bind us, open and feed channels of friendship. Like everything else in life, we need navigational skills, to know how to create a good day for ourselves. 

When we look for humor, beauty, or joy, emotions can be instantaneously performed in a single smile. That's perhaps the simplest skill to build a good day by making a choice involving our emotions, thinking, and behavior.