The key to saving for retirement is to start as soon as you can. Many would-be investors end up waiting on the sidelines because they feel like they don't have enough money to justify getting started. Yet with one basic strategy, you can begin putting your investment dollars to work right away and actually take advantage of favorable conditions right off the bat.The strategy is called dollar-cost averaging, and not only does it fit well with the way most people budget their savings, it also does a good job of handling volatile markets.