Being yourself means respecting your own decision, doing what feels natural to you and staying true to your heart. It is a first step towards realizing your personal growth.
Respect others as much as you respect yourself. Learn the good skills and habits from them but never try to imitate anyone. Each person has different priorities and experiences in life, there is no one else who wants to achieve exactly the same thing as you do. Imitation implies that you have lost your dignity, and you are not liking something about yourself.
Hence figure out what you like and dislike about yourself. The thing you like is already part of yourself. The thing you dislike about yourself is a limitations which are blocking your way to be yourself.
Some limitations like colour, height etc. can not be removed and you will have to live with them. But some limitations like a pimpy face, overweight, lack of confidence, hesitation etc. can be removed. But it is also true that you can not remove it overnight. You have to continuously work on it until it gets completely removed.
Finally by removing your limitations, which you can remove, you will not only improve your dignity but also cover up those limitations which can not be removed. As a result, you will enhance your self respect, start doing things which you like and above all you will be yourself.