Many people say “Just be yourself”, and this is an incomplete answer. Self-help “gurus” would suggest something along the lines of “being your best self”. While I think this is a better response than the former, it is also incomplete. I believe it is incomplete because in order to be your best self, you would need to know who you are first.
I believe being confident means to be certain in yourself, and a confident person is someone who has earned that right to be certain in himself. A person who has and continues to expand his domain.
What does confidence mean to you?