Intraday Trading is an approach of complete discipline. Here are Some mistakes you can avoid to become successful in the market:
1) You should have a proper plan, with entry exit and target points. And then stick to your setup while trading and should not change decisions on the basis of emotions.
2) Follow the risk management to avoid making big losses. Don't take risks of more than 1-2% of your capital.
3) Trade with the trend in the market and should not trade against the overall trend in the market
4) Don't enter or exit trade with panic and greed, try to control emotions to be profitable