Learn from the blunders of others to avoid repeating them.

Are you investing your hard-earned savings? If the answer is "yes," then congratulations! Whether your portfolio consists of stocks, mutual funds, bonds, savings accounts, or certificates of deposit, you have taken the first and most important step toward a secure and growing nest egg.

Even so, you should know about a few of the most common--and worst-mistakes you can make as an investor. Don't fall into the same traps as your neighbor, your Uncle Pete, and untold millions of investors before you.

No clear strategy

It's almost too easy to invest these days, with online discount brokers and local banks giving you access to investment vehicles that used to be the sole domain of professional money managers. Before you jump in with both feet, you need to have a plan that fits your risk tolerance, your long-term investment goals, and the amount of cash that you can put into a portfolio.

Not sticking to plan

What do you do if a company whose shares you own releases some bad news, and the stock price falls. Sell? What if you see a hot tip on TV and simply have to own some gold right now. Do you buy? Maybe the portfolio is growing too slowly, and you're sorely tempted to jump on the latest trendy asset to boost your returns. Do you back up the truck?

Not so fast, Sherlock. Put on your detective hat and figure out whether these changes really fit your goals. You might be able to get away with a few ill-informed decisions when retirement is decades away, but panic and gimmickry rarely help. There are no shortcuts to successful investing. Do your homework and stay on target.

Overconfidence

You need to have confidence in your ability to manage a long-term investment plan, but don't go overboard. Ask your friends about their driving skills, and 90 percent will claim to be "above average." The same brash audacity applies to investors as well-everyone thinks she's better than everyone else.

The Internet helps to give you much of the same information as every other investor out there, including the big boys (mutual fund managers, hedge funds, ultra-rich investors) whose actions really move stock prices. You can always hope for above-average returns, but it's a mistake to expect them when you build your investment plan. Set your return targets too high, and you'll end up eating noodles in retirement, because you thought you were saving enough when you really weren't.

Don't gamble...invest!

Stock certificates aren't lottery tickets, though many investors treat them that way. With each stub, you buy a small piece of the company whose name is emblazoned across the front of the document. Stock chart squiggles are a side effect of the business, not the reason for buying into the company. Treating your investments like the real companies that they are will help you stick to the suggestions offered above.