Answer:
Telling someone that he/she is enough will surely help his/her confidence boost. Complimenting him/her, telling her about the good things he/she has. On the other hand, the cause of the lack of self-confidence is how the society judges the physical feature of a person and saying all their thoughts about how bad that person looks. One of the causes too is that we always compare ourselves to others and that is why we think we're not good enough.
