Read books and articles on trading. Consider getting mentoring from someone you have followed and who's method you feel would work with your personality and needs. Invest in your own education, not trade signals you pay for each month or expensive subscriptions—these only serve to make you reliant on someone else. Invest in yourself from the start. That way, no matter what happens you have the skills to get the job done, on your own.

The first 9 successful trades produce $900 in profit. On the 10th trade, when the position is down $50, instead of except the loss the untrained trader purchases more shares at a lower price to reduce his cost basis. Once he is down $100, he continues to hold and is unsure of whether to hold or sell. The trader finally takes the loss when he is down $1,000.
Assess how much capital you're willing to risk on each trade. Many successful day traders risk less than 1% to 2% of their account per trade. If you have a $40,000 trading account and are willing to risk 0.5% of your capital on each trade, your maximum loss per trade is $200 (0.005 x $40,000). Set aside a surplus amount of funds you can trade with and you're prepared to lose. Remember, it may or may not happen.