Extras: Once the core of your portfolio is in place, you can play around with the extras and the niche or fancy funds. iShares S&P North American Natural Resources (NYSEArca: IGE) is a good example of this. (Do alternative ETFs belong in your portfolio?)

Becoming a good trader: Being a good trader involves education, time, patience, trial and error and a willingness to examine your good moves along with the bad ones. (10 tips to improve your ETF game).

A Plan: Last, but not least, you need a plan for investing. Assess your risk, your time horizon and your strategy. We use a trend following strategy, which you can read about in The ETF Trend Following Playbook.

For more stories about ETFs, visit our ETF 101 category.