Save Your Cash
"America needs a stock market crash."
In our current climate, it is very possible. If you are young, the best thing to do is save your cash and buy after it crashes. If you are old, you should have a significant portion of your money outside of stocks.
I've come around to the idea there are only two ways to smartly buy stocks: on a regular dollar-cost-averaging basis and/or when they are ridiculously low and you can't possibly lose money in the long run. All other retail purchases are speculative. Hoard cash for the once every five to ten years when stocks go super low because that's the only time to buy.