I use ETF (exchange traded funds) bonds and stocks. Stay away from single stocks and bonds, unless you like to gamble and know what your doing. Weight them accordingly to your retirement horizon.
On the bond side: keep in mind that interest rates will be going up within the next year or 2 so keep to short term bonds or bonds with a low durations. High yield corporate bonds can earn you a lot right now but they are high risk. GNMA bonds are pretty safe. I like PIMCO and Vanguard bonds.
On the stock side: twenty five percent of your stock holdings should be in foreign stocks and currency. Emerging markets like VWO, developed markets like EAF index. I also like EWC,EWZ,EPP,EWS,EWH. I think the real growth going forward is outside the US. I like VB for small caps. DBC, MOO,XME, OIH,GLD ETP for commodity/resources. I also like high dividend yield ETF's. I like GBT for large cap overseas exposure and good dividend yield. XLV for health play.
Remember in the past it was hard to beat the S&P index unless you were a day trader or put all your eggs in one or 2 stocks and get lucky.
Most people will brag about their hits and never about all their failures.