(a) Look for a successful day trading system which has perfected the art of making money from stock market trading. Look fro a trading mentor.
(b) Trade with a plan to avoid falling in category of gamblers.
(c) Day trading is a profession by itself and thus demand your dedication and get good trading education like one can go through all the articles on the site and one is ready to start trading.
(d) Be ready to learn from stock market every day and invest time in learning the market.
(e) Make a diary to record your trades to learn from successes and failures.
(f) Keep the emotions under check as it is a sure shot recipe to fall in a losing trade. Remember that emotional people tend to break under pressure. Try to stay calm, don't take your defeats too seriously and simply follow the plan.
(g) Invest in share market with the money which one can afford to lose. Do not trade with borrowed money or money kept to pay your bills.
(h) Avoid tendency of over trading in exuberance which is a sign of an amateur trader. Many people commit this mistake as an effort to cover their losses, but it can be a recipe for disaster.