There are most useful personality development tools given in this video by professional Psychologist Jyoti Bendale.

You will get handy tips for personality development as well you can categorize others' personlaity also.
You will learn about 'Triguna Theory of personality' by watching this video.

Do watch to know more about your personality traits and improve your personality.

You will get more insightful videos on my YouTube channel.
Please search my channel by name - Jyo's Tips by Harshdeep or Jyoti Bendale.