Change the Way you Talk to Yourself  "Self Talk"
Self-confidence is one’s belief in oneself. It refers to an individuals confidence in their actions, beliefs and competencies. Having self-confidence is the key towards a successful and fulfilling life.
Self-talk can be described as that little voice inside a person's head which can either be beneficial or detrimental to their self-confidence. This inner voice can comment on,  praise or criticise an individuals  actions.
There are different views about self-talk in relation to building self-confidence. Some individuals identify self-talk as the main obstacle that inhibits them from achieving their gaols.  Self-talk can indeed be the source of low confidence and ultimately failure,  especially when the person does not make a concerted effort to resist negative thought patterns. 
Conversely self-talk can be an important tool in developing self-confidence, when the inner voice can be seen as a teacher,  mentor,  critique (constructive) and a friend. Self-talk has been successfully employed by high achievers in all walks of life.
Here are a few helpful tips on how to utilize self-talk to develop a healthy self-confidence:
1) Listen to your inner voice
This is the first step towards cultivating positive self-talk. Identify the inner voice in you and listen to what it is saying. Ask yourself questions  regarding the contents of the thoughts, the situations which brought them about and any other contributing factors.   For this to be effective, you need to be as honest as possible.
2) Thoughts Assessment
After your thoughts have been identified, it is now time to assess them. What are your thoughts saying in general? What attitude towards yourself is being projected?  How have you responded in the past?  Which thoughts have been repeated so often that they have become a habit? Have any of your thoughts been helpful to you in your quest towards increased self-confidence?
Another important thing to assess is the way you respond to your inner voice. Some people find that their  negative thoughts are actually empowering; as it gives them a much needed push towards the attainment of their goals. Negative thoughts can be helpful in the short term if they get you to change an attitude or action,  however, they can become harmful over time.  Repetitive negative thoughts tends to instil a general feeling of hopelessness and incompetence, especially if, like most of us, you have tasted failure a few times. 
Viewing life in a positive light is the way towards building self-confidence. When a person stumbles down, the inner voice should say “stand up, you can do it!” rather than “you’re pathetic, stay down before you hurt yourself again!”
3) Exchange negative for positive thoughts
Dealing with your inner voice can be a daunting task. The goal is to get rid of your negative thoughts thus making room for positive ones to take their place. This is easier said than done, because it involves making a conscious effort to refrain from thinking about the negative, and deliberately thinking about something positive instead.  Strive not be a slave to the thoughts in your head, take control. A good way to take control is to speak  positive affirmations out loud.  Over time, the act of exchanging negative for positive thoughts will become a habit and result in creased self confidence.
Self-confidence is like a pair of eyeglasses, wearing the right pair can make one enjoy the beauty of your surroundings, while wearing the wrong ones will give you a blurred distorted view of the world.  Taking this statement one step further, life is about perception and attitude. No one will never enjoy life while filled with negative perceptions and attitudes.  The trick is to exchange these for positive ones, in how you perceive yourself, others and the world at large. This will not only increase your self confidence, but it will also increase your overall happiness.