Make sure you have the courage to stay true to your convictions and not let the market affect your emotions.
You have to be a little aware of the emotions of the people who have invested with you.
Don't be afraid to be a loner but be sure that you are correct in your judgement.
Have patience. Stocks don't go up immediately.
Some kinds of stocks are easier to analyse than others.
Warren is a very good judge of people and he's a very good judge of businesses.