Let's cut to the chase: The surest way to sabotage your retirement is to do nothing at all. Don't save. Don't invest. Don't assess your time horizon, don't worry about tax efficiency, don't even utter the words "withdrawal rate."

While that may be an obvious point, it's not too obvious to reiterate. Really -- the numbers don't fib. According to the Employee Benefit Research Institute's 2007 Retirement Confidence Survey, "almost half of workers saving for retirement report total savings and investments of less than $25,000."

This is dedicated to half the U.S. workforce
To give yourself a chance at a truly golden retirement, don't let inertia take hold of you -- in either your saving or your investing.

Saving more money every month is about self-discipline; find a few spare dollars here and there, sock them away, and let them compound. Easy enough, at least in the abstract.

When it comes to investing, though, inertia can take shape because of the overwhelming options available to investors, many of whom have scant experience picking their own investments.

With that in mind, follow the advice of Whitney Tilson, a fund manager who visited the Motley Fool Rule Your Retirement camp to share some words of wisdom. Tilson said that when addressing the equity part of your portfolio, you essentially have three options:

  1. Invest in mutual funds.
  2. Invest in index funds.
  3. Pick your own stocks.

Simple, huh? But which one is right for you? 

Mutual funds, mutually troublesome
Most investors choose option No. 1. But as a group, mutual funds underperform the market -- and some investors jump into the hottest funds at the wrong time, just before they're about to dip.

Tilson cited a study that showed that while the average stock mutual fund posted a 12.3% yearly return from 1984 through 1995 (vs. 15.4% for the S&P 500), the average investor in a stock mutual fund actually only took home 6.3%.

Why the discrepancy? Investors too often chased the hot funds and bought at the wrong time, right before the fund slowed down or tanked. In fact, the typical mutual fund investor would have ended up with nearly twice as much money during those 12 years by simply buying and holding the average mutual fund -- and about 2.5 times as much by buying an S&P 500 index fund.

Don't be fooled: There are plenty of good mutual funds out there. Just do your due diligence, and know that a beaten-down sector is often a great place to start. Be contrarian.

Taking index of index funds
OK, if I scared you with my mutual fund rant, perhaps you're thinking an index fund is more your thing. Sure, index funds offer a conservative alternative to mutual funds -- and carry low fees to boot. Legendary investor Warren Buffett has even claimed that index funds are "the most sensible" investment for the vast majority of Americans.

But there's a snag: You won't ever beat the market; you'll be betting alongside it.

The pick of the litter
Here's where it gets tricky. We'd all like to consider ourselves expert stock-pickers, but the truth is that analyzing companies and investing in individual stocks is hard, and few people have the time, training, and temperament to do it successfully over time.

But there's hope. Perhaps the best strategy for individual investors who want to try their hand at stock-picking is to buy a basket of blue-chip stocks and tuck them away for a long time (reinvesting dividends along the way).

Tilson and his partner manage the Tilson Focus Fund (TILFX) and the Tilson Dividend Fund (TILDX) -- and keep the funds populated with respectable stocks that they believe are trading at moderate multiples: Berkshire Hathaway  (NYSE:BRKb), Foot Locker (NYSE:FL), Wal-Mart (NYSE:WMT), Wendy's (NYSE:WEN), Anheuser-Busch (NYSE:BUD), and Costco (NASDAQ:COST), just to name a few.

Decisions, decisions
Retirement is always closer than you think, so now is the time to commit yourself to a savings plan and decide which investing route makes the most sense for you. Risk-averse investors should consider index funds, while investors who can stomach more volatility -- and increased costs -- should take a look at mutual funds (and avoid jumping into and out of the so-called hot funds). But investors who try their hand at picking individual equities might find just what they're looking for to juice their retirements.   

For help getting your plan on track, Robert Brokamp and his Rule Your Retirement service have all the tools for creating a successful retirement plan. A 30-day free trial to the service grants you access to all past issues of the newsletter, guest interviews like the one with Whitney Tilson, a host of retirement calculators, and our model portfolios.

Remember: The best way to ruin your retirement is to do nothing at all, so what are you waiting for? 

Fool editor Jill Ralph owns no shares of any company mentioned. Berkshire Hathaway and Costco are Stock Advisor recommendations. Berkshire Hathaway, Wal-Mart, and Anheuser-Busch are Inside Value picks. The Fool has a disclosure policy.