There are two things individual investors can control: how much money they put in their retirement portfolio and the fees that they pay. They should maximize the first and minimize the second.
High fees will destroy your wealth. But individual investors aren't the only ones who can end up paying too much for investment services. Consider the case of the Libyan Investment Authority. You'd think that these guys would be able to get a pretty good beak on the fees paid. Not so as the FT reports. In some cases the fees paid were approaching 10% of the fund's asset value.
So remember, it doesn't matter whether you are just an ordinary investor or a crazy dictator of an oil rich nation, you need to watch out how much you are paying in fees.