The best strategy is to contribute as much as you can as early as you can. Thinkstock By the editors of Kiplinger's Personal Finance Updated January 2015 The best 401(k) strategy is simply to contribute as much as you can as early as you can.First, because you don't know what the future may hold: unemployment, disability or even the decision by one parent to stay home with the kids. See Also: The Basics Special Report Second, the sooner you begin saving, the sooner you can harness the power of tax-deferred compounding. For example, say you'll need $1 million in your 401(k) when you retire in 40 years. Assuming an 8% annual return, you'll need to stash $286 a month in your 401(k). But put off saving for 10 years and that monthly savings figure jumps to $671 per month; wait 20 years and you'll need to shell out nearly $1,700 a month. Use our Power of Boosting 401(k) Contributions calculator to find out how fast your retirement savings would grow with regular contributions. Maybe you find yourself unable to sock away the maximum amount in your 401(k) plan. That's okay. Try at least to defer enough to claim the full employer match if your plan offers one. You don't want to pass up free money.