You can use these strategies to help build up, tune, and improve your self-confidence.  Butler and Hope write:

• “Practice”
• “Behave as if you are more confident than you are.”
• “Be flexible in your behavior.”
• “Learn from your mistakes.  The only way to avoid mistakes is to become stagnant.”
• “Silence the voice of self-blame, and speak encouragingly to yourself.”
• “Be kind to yourself.”

Don’t be your own worst critic.  Be your own best coach.  Learn from your mistakes, but encourage yourself to new heights.  Butler and Hope write:

“Apply the ‘water-under-the-bridge’ rule, and operate a statute of limitations.  Kicking yourself for past inadequacies, confusions, or failures gives fuel to your internal wavering voice — cut off its supply of oxygen and use an encouraging voice instead.  Imagine you had a champion whose job it was to bring the best in you.  What encouraging things would this person is whispering in your ear?  Amplify those messages, so you can hear them loud and clear.”