The problem most new traders make is that they don't practice a strategy in a demo account, for several months or more, before risking real capital. Therefore, they have no idea how a strategy works, and how they need to adjust it when market conditions change. The demo accounts serves as a testing ground, where new traders can test out ideas, see what works and hone trading psychological skills (such as patience, discipline and focus).
Order execution: A novice needs to master the art of efficient order execution. A delayed or bad order can wipe out what little profit was earned and even result in a loss. Since the profit margin per trade is limited, the order execution has to be accurate. As mentioned above, this requires supporting systems such as Direct Access Trading and Level 2 quotations.
Sincere interviewed professional day trader John Kurisko, Sincere states, Kurisko believes that some of the reversals can be blamed on traders using high-speed computers with black-box algorithms scalping for pennies. “That’s one of the reasons many traders get frustrated with the market. The timing is not like it used to be, and many of the old rules don’t work like before.” 
Day trading is the act of buying and selling a financial instrument within the same day or even multiple times over the course of a day. Taking advantage of small price moves can be a lucrative game—if it is played correctly. But it can be a dangerous game for newbies or anyone who doesn't adhere to a well-thought-out strategy. What's more, not all brokers are suited for the high volume of trades made by day traders. Some brokers, however, are designed with the day trader in mind. You can check out our list of the best brokers for day trading to see which brokers best accommodate those who would like to day trade.