Diversify Your Investmentsby Amy Fontinelle
If you don't have all of your money in one place, your paper losses should be mitigated, making it less difficult emotionally to ride out the dips in the market. If you own a home and have a savings account, you've already got a start: you have some money in real estate and some money in cash. In particular, try to build a portfolio of investment pairs that aren't strongly correlated, meaning that when one is up, the other is down, and vice versa (like stocks and bonds).
Source: http://www.investopedia.com/articles/pf/08/recession-proof-your-life.asp; http://www.twopenniesearned.blogspot.com/