As an intraday, can you tell me some basic things that I need to be aware of and always keep in mind?
Answer 
You can do intraday trading both ways. That means you can buy and sell to close out the position and you can also first sell and then buy back to close out the position. Therefore, intraday trading can be on the short side or on the long side. You can buy the shares in the morning and sell the shares by evening or you can sell it in the morning and buy it back the same day. Short selling is only permitting in intraday trading in India since Indian markets are in rolling settlement. If it is not closed by end of the trading day then you need to necessarily take delivery of or give delivery the shares, as the case may be.
In an intraday trade, the net position at the end of the day is zero. That means, intraday trading does not really impact your demat account as there is no delivery. Only your net position is considered for delivery. That means if you buy 1000 shares of Tata Steel and sell 800 intraday, then only 200 shares go for delivery into your demat.
Since they do not involve and clearing and delivery settlement, intraday trades require lower margins than delivery trades. Mostly, brokers will charge only a percentage of the full margin for trades that are specifically marked for intraday trading only. Such trades, if not closed by you, will be terminated by the broker.
You must not trade intraday without a stop loss which acts like an insurance for your trading position. Stop losses are a must for intraday trading. Since you are normally leveraged in an intraday trade, any sharp correction in the market can result in huge losses. It is always better to keep a technical stop loss or an affordability stop loss. Putting a stop loss in your intraday trade can also reduce your margin requirement. Such orders are called cover orders and if stop-losses are built into the trade then the margins are lower for those specific intraday trades.
Trading is all about risk reward and when you trade short your profits will also have to be short. Don’t keep too aggressive profit targets in intraday trading as the idea is to churn your money rapidly. Always maintain your risk-reward ratio between your stop loss and your profit target. Ideally, put your profit target as part of your order itself. Don’t let profit be an afterthought.
Intraday trades cannot be done on Trade-to-trade (T2T) stocks. These are stocks that are specifically marked only for delivery and if you buy these stocks with the intent of trading intraday, you will be forced to take delivery on these stocks. Also intraday trades are not permitted in Z group stocks since they are also marked purely for delivery only.
What many of us do not normally appreciate is that these intraday trades typically provide liquidity in the market. Some of the biggest intraday traders in the market are proprietary traders, HNIs and a few retail investors. Institutional investors are not permitted to trade intraday in the markets. They are mostly on compulsory delivery mode only.
Protection of capital and stemming of losses is the key. That is why in intraday trading always aim to protect your capital. That is your first priority. Returns can follow after that. If you find the market too volatile, it is better to stay out of the market rather than get caught in the volatility of the markets. When it comes to intraday trading, you must be careful about the stocks that you choose. Avoid penny stocks and highly illiquid stocks where the tracking cost could be quite high. It is always best to stick to the 100 most liquid stocks in the market. Ensure that the spread are narrow, the ticks are small and the volumes are sufficiently liquid. Unlike what a lot of market observers believe, intraday traders are not speculators or punters. They trade on a combination of technical charts and news flows. Keeping yourself updated about the latest on stocks and indices with their implications is the key to success in intraday trading. They actually help in discovering prices and create liquidity in the market on shorter ticks.
One of the most important aspects of intraday trading is timing your trade right and it really matters a lot in intraday trading. When trading large quantities on small spreads even a small price tick matters a lot! That is why using precise levels to time your trade matters a lot. That is the reason, intraday traders make extensive use of technical analysis as they are more interested in short term trends within the broader gamut of longer term trends. It is by capturing these trends a little early that intraday traders are able to make money.
Intraday trading, on any average day accounts for 50-60% of the total volumes on the exchanges and is a substantial contributor. More importantly, it provides the liquidity and volumes that makes the markets safer.
Finally let us dwell briefly on the taxation aspects of intraday trading. Intraday trading is treated as Speculative Business Income because there is clearly no intent of taking delivery. Thus intraday losses can only be set off against intraday profits and not against other gains. Note that futures and options even if done for intraday purposes are not treated as speculative since the purported intent is to hedge.