Speak only when it is required to speak.
Listen more, speak less. Otherwise, don't even speak. While speaking, focus on tonality, speak in a low tone and understandable manner. Don't forget to put a smile in your face when you are talking to someone.
Learn to control your emotion.
To develop a strong personality, first, you need to have absolute control over your emotions. Things may not be good always, but when things get bad, don't lose faith. Don't let bad things or bad situations determine your future, have absolute control over them.
Dont be slave to your emotions, control them.
Dress like you are the king.
There’s a popular saying, ‘Dress how you want to be addressed’. Dressing well will make you feel good about yourself. When you feel good about yourself, you are most probably gonna feel good about yourself. Dressing well is one of the quickest ways to improve your self-confidence.
Be an active listener.
Listening is a fine art. Listening will bring you more success in social interactions. Practice listening and soon you will see the change in your life.
Develop the habit of reading book.
Reading books will improve your vocabulary and communication skills. If you cannot read a full book, read a book summary. It's better to know something than nothing.