There are some common tenets that many great investors follow that you can use, too.
From Whitney Tilsen and John Heins, contributing editors at Kiplinger's magazine, here are four tips to become a better investor:
Invest in businesses, not in stock. Don't spend too much time poring over the stock pages or obsessing over stock-price movements. What you should be focused on is the business fundamentals behind the stock price. Put some time into researching a company's strengths and weaknesses, how competitive it is within the industry and how it might grow in the next 10 years.
Don't go outside your comfort zone. Many great investors, Warren Buffet included, emphasize the importance of investing in what you know. If you invest in something you understand, then you will be better informed about how the company should perform in the future.
Go against the grain. Being a successful investor requires a certain degree of independent thinking. What the consensus thinks about a company is often already baked into the stock price. If you bring some original thinking to investing, you might see something that no one else does.
Don't be afraid to do nothing. Many investors feel tempted to continually reconfigure their portfolios. But all that tinkering often leads to losses. Once you buy a stock, plan to hold on to it for several years.
Marshall Loeb, MarketWatch