I did a fair amount of technical analysis trying to learn day trading a few years ago. I've also bought and sold stocks based on fundamentals, trends or hunches. I lost money and I made money. The best returns I had were from buying stocks in 2008/2009 during the crash (duh) and holding.

My approach now for long term investing is to auto invest monthly into 5-6 index funds w low fees, aka Bogelheads. Simple, low stress. Dollar cost average on auto-pilot.

Also, set aside a nice chunk of cash to invest during the next crash.