Every human being has locked within themselves vast storehouses of unlimited potential. Your purpose as a Mentor/Teacher is to provide a fertile ground for self confidence to grow.
The first step in helping a child grow self confident is examining your own self confidence. You are perfect just as you are because there is nobody like you in the past, present or future. Being perfect is simply doing the best that you are capable of in each task.
Yes, you will falter at times. Part of being perfect is admitting mistakes and not making them twice. Just believe that you are capable of growing in a more excellent way - everyday. Overcome adversity by envisioning a new season of Spring in the midst of Fall. All things change together for good.
Thanks for your time.
Go do something nice for somebody.