Stocks give you the best shot at high returns, having returned more than 10% a year since 1926, twice the return of bonds. So stash a big chunk of your portfolio in equities - 70% is a reasonable amount if you are investing over a couple of decades, says Kevin Sale, a financial adviser in Bloomington, Minn.

If you don't consider yourself a stock picker, a broadly diversified index fund - tracking either the S&P 500 or Wilshire 5000 - is a perfectly reasonable option.

Key stat: Most wealth of millionaires comes from job earnings (32%). Just 16% is inherited.