A candidate can prepare it in advance as the questions are already known and for that you can refer to your parents friends, etc and ask them what they feel about you.
Also ask them one or two bad points about you and make sure that you can justify it. Suppose your parents say that you are extravagant then you can justify it by saying that I always go for quality products that's why they think I am extravagant.
The best way to handle Self-Description test is to describe your character in less words but with various qualities. E.g: you want to say “I am a responsible boy I am a funny loving and friendly person.” Instead of it write “I am a responsible, loving and friendly person.”
Also avoid writing the qualities that go against OLQ's they need. E.g: My teachers say that I lack in decision making. This will be against you.
Give one or two negative points about you in the first 3 paragraphs and make sure that you can counter it. In self opinion there is no need to tell about your negative points. IO will ask you separately that what do you think what are your weaknesses? If you don't know about your weaknesses then go for what your friends or teachers say about you.
It is certain possibility that whatever you write in your SD, the interviewing officer will ask questions regarding that. Suppose you have written that ‘My parents see me as a helpful child as I help them in buying items from market'. Then be sure that you know the current item rates in the market.
Suppose in you have written that you want to improve your physical stamina then there will be a counter question. Okay, Ashish what you are doing to improve your physical stamina, what type of exercises you do to keep yourself fit.
Last but not the least write as many points you can write in less words, maintain speed and keep you handwriting neat and clean.
