Singles Not Home Runs:
If you make a solid annual return of 10-12 percent on your investments, you're doing fine. You can get that rate by picking your stocks quarterly rather than slaving away as some day traders do for twelve hours a day (only to go up 50 percent one day and then down 75 percent the next.) Get good stocks and hold on to them.

But How Do You Pick The Right Stock To Buy And Hold? 
The trick is to look for both growth and "value" (meaning the rest of the market isn't paying the price the stock is "worth"). 

Invest Regularly:
If you have a set amount taken from your paycheck every week to invest in a certain stock, you will sometimes end up buying when the stock is a little higher than normal, and sometimes when it is a little lower. This is called dollar cost averaging. By buying consistently, you will generally do better than those who try to guess the market. You can do this automatically if your employer has direct deposit, or as an automatic transfer from your bank account. Buying directly from the company lets you avoid paying a commission on these buys. (Most have programs for people who buy on a regular schedule. You can even buy fractional shares.) 

The best investment approach is to buy and hold. Do not listen to the day traders who think that holding something long term means keeping it past lunch. The great investors (Warren Buffet for example) buy a stock and hold on to it for five to ten years (sometimes much longer). When the market goes down, they buy more stock (at much lower prices). If you bought Dell Computer at the beginning of the decade and kept reinvesting dividends, you'd have a return of 57,282 percent.

Diversified Portfolio: 
When you look at your investments, don't just look at the individual securities; look at your overall makeup. Don't just lump everything into a few securities or industries. For instance, it's not a good idea to invest in five different steel companies. You should have at least 10 separate high quality securities, spread around different sectors. Don't get complacent by filling your portfolio with mutual funds (which usually invest in 100 securities). Be sure that your mutual funds are also spread across a variety of sectors. 

Industrial Strength: 
If you know an industry really well, or can see that an industry will soon be emerging into a new era of growth, try to catch the wave in its early stages. The best way to get early insight is to read the trade journals in that industry and invest in what looks like the growth leader (assuming your fundamental analysis warrants it).