I concur with the position that it is extremely difficult to beat the market with active trading/mutual funds.  I have an account that is strictly for trading during "maximum pessimism" (ie XEG in Jan/Feb and selling for a nice profit as well).

My main investment account is stress-free and simple ETFs (Canada, US, Int'l and Emerging Markets plus some bonds and preferred shares).  Assess every 3-4 months and buy more units of the laggard ETF.

Diversification and low cost and two of the most important aspects.