The most important practice when investing in stocks is to know your goal and to know your risk. Each stock investment comes with a risk, and you need to make sure you understand how risky that stock investment is before you make it. It is important to know your investment may go down in the short term and be willing to ride out the ups and downs of the stock market. It can be useful to set stock prices so that you will sell out of the stock if it goes down to a certain share price or if it goes up to a certain share price.