Simple trick of acting confident

Confidence is crucial to one’s success in life. Use this trick to help you and feel more confident.
One of the most famous psychologist that America has produced, Professor William James wrote:
Actions seem to follow feeling. Movement and emotion go together. 
By regulating the action, which is under more direct control of the will, we can indirectly regulate the feeling which is not.
Your joy is lost then try to sit up cheerfully and to act and speak as joy were already there
So to feel brave, act as if you were brave. Use all your will to that end and a courage fit will very likely replace the fit of fear.
If you feel that you are not confident or courageous enough when you face different situations try this technique:
To overcome fear to the dentist. To overcome the fear of giving a speech in front of the class or school. Or to overcome that feeling of being anxious when you are talking to a group of people.
All people act and feel based on mental pictures they have created during their life. How can they act otherwise?
If you want to overcome fear or being anxious in a particular situation, change the mental picture you have related to that case.
For example, if you fear to go to the dentist, imagine yourself as a person with total confidence and courage. 
Imagine all the details when you are sitting in the dentist chair, hands of the dentist approaching to your mouth, smell of the placeAll the things that you notice. 
At the same time try to feel confident and courageous. Repeat this exercise several times.

Your imagination should be vivid and detailed. Your imagination practice is equal to an experience

See yourself acting and reacting appropriately, successfully, ideally
Imagine how you would feel if you were already the sort of personality you want to be.
If you have been shy and timid, change the self-image. See yourself moving among people with ease and poise and feeling good about it. 
If you have been fearful and anxious in certain situations, see yourself acting calmly and deliberately, acting with confidence and courage.
This exercise builds new “memories” or stored data into your midbrain and central nervous system. It creates a new image of self. 
After practicing it for a time, you will be surprised to find yourself “acting differently“more or less automatically and spontaneously, without trying.