Taking a company pension distribution in cash. Uncle Sam takes 20 percent withholding before you even see the check. You can draw money from your IRA as you need it and defer taxes on the rest. Not anticipating inflation. Inflation won't retire when you do, so you'll have to depend on the growth of your nest egg to keep up with increasing costs.
Stocks are one of the best weapons for fighting the effects of inflation.
Putting all your eggs in one investment basket. To minimize risk, maintain a diversified investment mix of stocks, bonds and money market funds. A family of mutual funds will allow you to transfer money from one fund to another with ease, to maintain the diversity you need. Tapping your retirement income too soon. Some retirees go on a spending spree as soon as they retire, and they regret it later.