Personality is determined by heredity, environment, and situation. Heredity influences physical traits like appearance and temperament through genes. Environment, such as family and culture during upbringing, also plays an important role in shaping personality. Additionally, an individual's personality can change in different situations depending on constraints imposed. Some ways to develop a good personality include having confidence, dressing professionally, appreciating others, speaking respectfully, maintaining a positive attitude, accepting limitations, and knowing oneself.